{"$schema":"nativecad-dfm-pack/1","id":"marine","title":"Marine — hulls, deck hardware, through-hulls, corrosion and outboard mounting","sector":"marine","version":"2026-09-03","summary":"Hull scantlings by ISO 12215-5, deck-hardware and cleat sizing, through-hull/seacock hole sizes and waterline rules, marine fastener and galvanic-isolation practice, drainage, outboard transom heights, and the ISO/ABYC/USCG tests and materials a small-craft part is held to.","aliases":["boat","hull","deck hardware","cleat","seacock","through-hull","transom","outboard","bilge","stanchion","yacht","dinghy","kayak"],"crossSector":false,"size":"standard","sources":[{"id":"iso-12215-5","title":"ISO 12215-5:2019 Small craft — Hull construction and scantlings — Part 5: Design pressures for monohulls, design stresses, scantlings determination","url":"https://www.iso.org/standard/72178.html","accessed":"2026-09-03"},{"id":"iso-12217","title":"ISO 12217-1/2/3:2015 Small craft — Stability and buoyancy assessment and categorization","url":"https://www.iso.org/standard/61478.html","accessed":"2026-09-03"},{"id":"abyc-h27","title":"ABYC H-27 Seacocks, Thru-Hull Connections, and Drain Plugs","url":"https://abycinc.org/page/StandardsCatalog","accessed":"2026-09-03"},{"id":"abyc-h40","title":"ABYC H-40 Anchoring, Mooring and Strong Point Design and Installation","url":"https://abycinc.org/page/StandardsCatalog","accessed":"2026-09-03"},{"id":"abyc-e2","title":"ABYC E-2 Cathodic Protection","url":"https://abycinc.org/page/StandardsCatalog","accessed":"2026-09-03"},{"id":"iso-9093","title":"ISO 9093:2020 Small craft — Seacocks and through-hull fittings","url":"https://www.iso.org/standard/71651.html","accessed":"2026-09-03"},{"id":"iso-15083","title":"ISO 15083:2019 Small craft — Bilge-pumping systems","url":"https://www.iso.org/standard/71218.html","accessed":"2026-09-03"},{"id":"uscg-33cfr183","title":"33 CFR Part 183 — Boats and Associated Equipment (US Coast Guard)","url":"https://www.ecfr.gov/current/title-33/chapter-I/subchapter-S/part-183","accessed":"2026-09-03"},{"id":"bs-1088","title":"BS 1088-1:2018 Marine plywood — Specification for the quality of timber and manufacture of plywood for use in marine environments","url":"https://www.bsigroup.com/","accessed":"2026-09-03"},{"id":"gerr-boat-strength","title":"Dave Gerr, The Elements of Boat Strength (International Marine/McGraw-Hill, 2000)","note":"Reference text for scantling rules of thumb, stringer spacing, and galvanic series practice","accessed":"2026-09-03"},{"id":"outboard-shaft-length-guide","title":"BoatUS / outboard-industry transom-height and shaft-length convention (short/long/XL shaft)","url":"https://www.boatus.org/","accessed":"2026-09-03"},{"id":"astm-b98","title":"ASTM B98/B98M Standard Specification for Copper-Silicon Alloy Rod, Bar and Shapes for General Purposes (silicon bronze)","url":"https://www.astm.org/b0098_b0098m-19.html","accessed":"2026-09-03"},{"id":"astm-b928","title":"ASTM B928/B928M Standard Specification for High Magnesium Aluminum-Alloy Sheet and Plate for Marine Service (5083/5086)","url":"https://www.astm.org/b0928_b0928m-19.html","accessed":"2026-09-03"},{"id":"astm-a276","title":"ASTM A276/A276M Standard Specification for Stainless Steel Bars and Shapes (Type 316)","url":"https://www.astm.org/a0276_a0276m-17.html","accessed":"2026-09-03"}],"entries":[{"id":"iso-12215-design-categories","kind":"standard","tier":1,"title":"ISO 12215-5 design categories A-D and their design pressures","summary":"ISO 12215-5 scantlings scale with design category: A (ocean, wind >40kn, wave >4m), B (offshore, ≤40kn/4m), C (inshore, ≤27kn/2m), D (sheltered, ≤18kn/0.5m) — the same hull dropped from category A to D can shed 30-50% of its bottom-panel thickness.","applies":["hull","scantlings"],"value":{"options":["A","B","C","D"]},"basis":"ISO 12215-5 Table 1 design category definitions drive every downstream design-pressure formula","sources":["iso-12215-5"],"tags":["iso12215","design-category","scantlings"]},{"id":"grp-single-skin-bottom-thickness","kind":"dimension","tier":1,"title":"Single-skin GRP bottom laminate thickness by LOA","summary":"A single-skin E-glass/polyester GRP bottom panel runs about 6 mm on a 6 m boat up to 12 mm on a 12 m boat (design category B/C planing hull), roughly linear with LOA — always confirm against an ISO 12215-5 panel calculation, this is a starting estimate only.","applies":["hull","grp","fiberglass hull"],"value":{"min":6,"max":12,"unit":"mm"},"basis":"ISO 12215-5 design-pressure and panel-size scaling for single-skin bottom laminates, category B/C","sources":["iso-12215-5"],"tags":["hull","grp","thickness","bottom"]},{"id":"cored-deck-panel-skins","kind":"dimension","tier":1,"title":"Cored deck panel: skin and core thickness","summary":"A cored deck panel typically pairs two 2-3 mm GRP skins with a 12-25 mm core (balsa, Coosa or foam); thin skins carry the in-plane/bending load while the core sets panel stiffness — going below 2 mm skin risks print-through and puncture.","applies":["deck","cored panel","sandwich construction"],"value":{"table":[{"param":"skin","min":2,"max":3},{"param":"core","min":12,"max":25}],"unit":"mm"},"basis":"ISO 12215-5 sandwich-panel scantling method: skin thickness from in-plane stress, core thickness from panel deflection/shear","sources":["iso-12215-5"],"tags":["deck","cored","sandwich","skin","core"]},{"id":"aluminium-hull-plate-thickness","kind":"dimension","tier":2,"title":"Aluminium hull plate thickness (small craft)","summary":"A welded 5083/5086 aluminium hull bottom plate runs 4-6 mm on boats in the 6-12 m range, thinner than the equivalent GRP laminate section because plate yields rather than fractures locally — topsides can drop 1-2 mm below the bottom-plate figure.","applies":["hull","aluminium hull"],"value":{"min":4,"max":6,"unit":"mm"},"basis":"ISO 12215-5 metal-hull scantling method for 5083/5086 plate at design category B/C","sources":["iso-12215-5"],"tags":["hull","aluminium","plate","thickness"]},{"id":"hull-stringer-spacing","kind":"dimension","tier":1,"title":"Hull bottom stringer/frame spacing","summary":"Longitudinal stringers or transverse frames under a GRP or aluminium hull bottom panel space 300-450 mm apart on a typical 6-12 m planing hull — closer spacing lets the panel scantling (and hence its thickness) shrink, the usual trade-off against added stringer weight.","applies":["hull","stringer","frame"],"value":{"min":300,"max":450,"unit":"mm"},"basis":"ISO 12215-5 panel unsupported-span input; Gerr's scantling rules of thumb for stringer spacing on planing hulls","sources":["iso-12215-5","gerr-boat-strength"],"tags":["hull","stringer","spacing","frame"]},{"id":"cleat-size-by-loa","kind":"dimension","tier":1,"title":"Horn-cleat length by boat LOA","summary":"Cleat size scales with boat length in a standard series: 150 mm (6 in) for dinghies/small runabouts, 200 mm (8 in) around 6-8 m, 250 mm (10 in) around 8-11 m, and 300 mm (12 in) for boats over ~11 m — undersizing a cleat concentrates line load onto a short horn and bends it.","applies":["cleat","horn cleat","deck hardware"],"value":{"options":[150,200,250,300],"unit":"mm"},"basis":"Common marine-hardware cleat sizing series matched to boat LOA and expected line diameter","sources":["abyc-h40"],"tags":["cleat","size","deck-hardware"]},{"id":"cleat-backing-plate-thickness","kind":"rule","tier":1,"title":"Cleat/stanchion backing plate minimum thickness","summary":"Every through-bolted cleat or stanchion base needs a backing plate of ≥ 6 mm 316 stainless (or aluminium) or ≥ 12 mm G10/FR4 laminate, spreading bolt load over enough deck-core area that a hard pull doesn't crush the core or pull the bolt through.","applies":["cleat","stanchion","backing plate","deck hardware"],"value":{"table":[{"material":"316 stainless / aluminium","min":6},{"material":"G10/FR4","min":12}],"unit":"mm"},"basis":"ABYC H-40 strong-point load-spreading requirement for deck hardware backing plates","sources":["abyc-h40"],"tags":["backing-plate","cleat","stanchion"]},{"id":"stanchion-dimensions","kind":"dimension","tier":1,"title":"Lifeline stanchion diameter and height","summary":"A lifeline stanchion tube is 25 mm (1 in) outside diameter in 316 stainless, 600-750 mm tall above the deck so the top lifeline sits around waist height; taller/thinner stanchions need a wall-thickness or diameter increase per ABYC H-40 load rules.","applies":["stanchion","lifeline","deck hardware"],"value":{"table":[{"param":"diameter","value":25},{"param":"height","min":600,"max":750}],"unit":"mm"},"basis":"Common 316-stainless stanchion tube stock size and ABYC H-40 lifeline height guidance","sources":["abyc-h40"],"tags":["stanchion","lifeline","diameter","height"]},{"id":"through-hull-nps-sizes","kind":"dimension","tier":1,"title":"Through-hull/seacock pipe sizes (NPS)","summary":"Through-hull fittings and seacocks are sized on the NPS (nominal pipe size) series 1/2, 3/4, 1, 1-1/4, 1-1/2 and 2 in — a bilge pump discharge is typically 3/4-1 in, a raw-water intake for a small inboard 3/4-1-1/4 in, and a cockpit drain up to 1-1/2-2 in.","applies":["through-hull","seacock","plumbing"],"value":{"options":[0.5,0.75,1,1.25,1.5,2],"unit":"in"},"basis":"ISO 9093 / ABYC H-27 seacock and through-hull nominal pipe size series","sources":["iso-9093","abyc-h27"],"tags":["through-hull","seacock","nps","pipe-size"]},{"id":"through-hull-hole-diameters","kind":"dimension","tier":1,"title":"Through-hull hull-penetration hole diameters","summary":"Drill the hull penetration to match the fitting's tailpipe OD, not the NPS nominal bore: common through-hull hole sizes are ⌀22, 29, 35, 48 and 60 mm for the 1/2 through 2 in NPS series — undersizing binds the tailpipe, oversizing starves the flange's bedding-compound seal area.","applies":["through-hull","seacock","hull penetration"],"value":{"options":[22,29,35,48,60],"unit":"mm"},"basis":"Typical bronze/Marelon through-hull tailpipe OD by NPS size","sources":["iso-9093"],"tags":["through-hull","hole","diameter"]},{"id":"seacock-waterline-rule","kind":"rule","tier":1,"title":"Through-hull placement above/below the waterline","summary":"Every through-hull below the waterline, or within 300 mm above it at maximum heel, needs a seacock with a positive shutoff bolted to the hull (ISO 9093 / ABYC H-27: 3 bolts on ⌀ ≥ 25 mm fittings); higher drains that can never submerge may skip it.","applies":["through-hull","seacock","hull penetration"],"basis":"ABYC H-27 requires a seacock on every through-hull that can be submerged in normal operation or at the boat's maximum heel angle","sources":["abyc-h27"],"tags":["seacock","waterline","through-hull","rule"]},{"id":"marine-fastener-alloys","kind":"fastener","tier":1,"title":"Marine fastener alloys: 316 stainless and silicon bronze","summary":"Above-waterline and general deck-hardware fasteners are 316 (A4) stainless; fasteners into bronze through-hulls, shafts or wood use silicon bronze so both sit close on the galvanic series — never fasten 316 stainless into aluminium without isolation.","applies":["fastener","hardware","through-hull"],"value":{"options":["316 stainless","silicon bronze"]},"basis":"Corrosion-resistant, low-magnetic marine fastener alloys matched by galvanic compatibility to the part they join","sources":["astm-a276","astm-b98"],"tags":["fastener","316","silicon-bronze","material"]},{"id":"galvanic-isolation-rule","kind":"rule","tier":1,"title":"Isolating stainless/bronze fasteners from aluminium","summary":"Never bed a 316-stainless or bronze fastener/fitting directly against bare aluminium — insert a 1-2 mm nylon or Delrin isolation bushing/washer and a non-conductive bedding compound, or the anodic aluminium pits and fails within one salt-water season.","applies":["fastener","aluminium hull","corrosion"],"value":{"min":1,"max":2,"unit":"mm"},"basis":"Galvanic series separation between stainless/bronze and aluminium drives rapid anodic attack on the aluminium without a dielectric break","sources":["abyc-e2","gerr-boat-strength"],"tags":["galvanic","isolation","aluminium","corrosion"]},{"id":"anode-sizing-by-water-type","kind":"dimension","tier":1,"title":"Sacrificial anode alloy by water type","summary":"Match the anode alloy to the water: zinc (−1.05 V) for salt, aluminium (−1.10 V) for salt or brackish, magnesium (−1.60 V) for fresh only — zinc passivates in fresh water within 2–4 weeks. Size anodes for 1 year at ≤ 50 % consumption.","applies":["anode","cathodic protection","corrosion"],"value":{"table":[{"water":"salt","alloy":"zinc or aluminium"},{"water":"brackish","alloy":"aluminium"},{"water":"fresh","alloy":"magnesium"}]},"basis":"ABYC E-2 anode-alloy selection by electrolyte resistivity and passivation behaviour","sources":["abyc-e2"],"tags":["anode","zinc","aluminium","magnesium","cathodic-protection"]},{"id":"limber-hole-diameter","kind":"dimension","tier":1,"title":"Limber hole diameter through stringers/frames","summary":"Limber holes that let bilge water pass under stringers and frames to the pump pickup run ⌀25-40 mm — too small clogs with debris and strands water in a compartment, too large weakens the stringer's shear web.","applies":["limber hole","bilge","stringer","drainage"],"value":{"min":25,"max":40,"unit":"mm"},"basis":"Common bilge limber-hole sizing balancing drainage flow against stringer/frame shear-web strength","sources":["iso-15083","gerr-boat-strength"],"tags":["limber-hole","bilge","drainage"]},{"id":"self-bailing-deck-height","kind":"rule","tier":1,"title":"Self-bailing cockpit sole height above waterline","summary":"A self-bailing cockpit sole must sit ≥ 150-300 mm above the static waterline (more toward 300 mm on a boat that squats under load or heels hard) so cockpit scuppers drain by gravity instead of siphoning seawater back in when the transom digs in.","applies":["cockpit","scupper","self-bailing","drainage"],"value":{"min":150,"max":300,"unit":"mm"},"basis":"USCG 33 CFR 183 and common small-craft practice for self-bailing cockpit freeboard over the loaded waterline","sources":["uscg-33cfr183"],"tags":["self-bailing","cockpit","waterline","drainage"]},{"id":"outboard-transom-heights","kind":"dimension","tier":1,"title":"Outboard transom height by shaft length","summary":"Outboard shaft length is set by transom height, top of transom to keel line: 15 in (381 mm) short shaft, 20 in (508 mm) long, 25 in (635 mm) extra-long, 30 in (762 mm) ultra-long — the wrong shaft cavitates (too short) or drags the lower unit too deep.","applies":["outboard","transom"],"value":{"options":[15,20,25,30],"unit":"in"},"basis":"Outboard-industry standard shaft-length series matched to transom height","sources":["outboard-shaft-length-guide"],"tags":["outboard","transom","shaft-length"]},{"id":"transom-thickness","kind":"dimension","tier":1,"title":"Outboard transom thickness","summary":"A transom built to carry an outboard runs 38-64 mm thick (cored GRP or solid timber/plywood core), scaling with engine weight and thrust; thin-transom boats need a doubler plate under the clamp/bolt pattern rather than relying on the raw laminate.","applies":["transom","outboard"],"value":{"min":38,"max":64,"unit":"mm"},"basis":"ISO 12215-5 transom scantling method scaled to outboard thrust and weight","sources":["iso-12215-5"],"tags":["transom","thickness","outboard"]},{"id":"deck-hardware-bolt-pattern-cleat","kind":"fastener","tier":2,"title":"Cleat base bolt pattern by cleat size","summary":"A 150 mm cleat typically bolts on 2 fasteners at its base (through the two horn feet), while 200-300 mm cleats bolt on 2-4 fasteners in an elongated rectangle matched to the cleat's own foot spacing; use M6-M8 (1/4-5/16 in) bolts sized up with cleat length.","applies":["cleat","fastener","deck hardware"],"value":{"table":[{"cleatLength":150,"bolts":2,"boltSize":6},{"cleatLength":200,"bolts":2,"boltSize":8},{"cleatLength":250,"bolts":4,"boltSize":8},{"cleatLength":300,"bolts":4,"boltSize":10}],"unit":"mm"},"basis":"ABYC H-40 fastener count/size scaling with cleat length and rated line load","sources":["abyc-h40"],"tags":["cleat","bolt-pattern","fastener"]},{"id":"hinge-hatch-conventions","kind":"feature","tier":2,"title":"Deck hatch hinge and lift conventions","summary":"Deck hatches hinge on the forward edge (so wind/seas can't flip them open) with a piano hinge or 2-3 surface hinges in 316 stainless plus a rated hold-open strut; hatch coamings run 50-100 mm above the deck to shed water before it reaches the seal.","applies":["hatch","hinge","deck hardware"],"value":{"min":50,"max":100,"unit":"mm"},"basis":"Common small-craft hatch-coaming height and forward-hinge convention to shed boarding water","sources":["abyc-h40"],"tags":["hatch","hinge","coaming"]},{"id":"through-hull-flange-dimensions","kind":"dimension","tier":2,"title":"Through-hull mushroom-head flange geometry","summary":"A through-hull's outer mushroom-head flange runs about 1.6-1.8x the tailpipe OD across (e.g. ~60 mm flange OD for a 35 mm tailpipe) with a 3-6 mm flange thickness, giving enough bearing area against the hull skin for the bedding compound to seal without the flange itself flexing.","applies":["through-hull","flange","seacock"],"value":{"min":1.6,"max":1.8,"unit":"ratio"},"basis":"Typical bronze/Marelon through-hull mushroom-head flange-to-tailpipe diameter ratio","sources":["iso-9093"],"tags":["through-hull","flange","dimension"]},{"id":"bronze-vs-marelon","kind":"rule","tier":2,"title":"Bronze vs Marelon (reinforced composite) through-hulls","summary":"Bronze through-hulls/seacocks for metal or mixed-metal hulls and engine lines above 60 °C; Marelon (glass-reinforced nylon) is immune to galvanic and dezincification attack and is the GRP default, but rated ~1.0 MPa / 82 °C versus bronze's higher limits.","applies":["through-hull","seacock","material"],"basis":"ABYC H-27 material guidance: bronze vs reinforced-composite through-hull selection by hull material and service conditions","sources":["abyc-h27"],"tags":["bronze","marelon","through-hull","material"]},{"id":"bedding-compound-thickness","kind":"dimension","tier":2,"title":"Bedding-compound layer thickness under deck hardware","summary":"Deck hardware and through-hull flanges bed on a 1-2 mm compressed layer of polyurethane or polysulfide sealant — thick enough to fill deck-surface waviness and seal the fastener holes, thin enough that squeeze-out under bolt torque doesn't starve the joint.","applies":["bedding compound","deck hardware","through-hull"],"value":{"min":1,"max":2,"unit":"mm"},"basis":"Common practice for polyurethane/polysulfide bedding compound compressed bond-line thickness on deck hardware","sources":["abyc-h40"],"tags":["bedding","sealant","deck-hardware"]},{"id":"countersink-for-sealant","kind":"feature","tier":2,"title":"Countersunk fastener holes as a sealant reservoir","summary":"Countersink deck-hardware fastener holes 1-2 mm deep at roughly 90 degrees before bedding so the sealant has a reservoir under the screw head instead of being squeezed out flush — a flush (non-countersunk) hole is far more likely to leak once the sealant ages and shrinks.","applies":["fastener","deck hardware","sealant"],"value":{"min":1,"max":2,"unit":"mm"},"basis":"Standard bedding practice for through-bolted deck hardware to retain sealant around the fastener","sources":["abyc-h40"],"tags":["countersink","sealant","fastener"]},{"id":"galvanic-series-positions","kind":"rule","tier":2,"title":"Galvanic series positions of common marine metals","summary":"In seawater, most anodic to most noble: magnesium, zinc, aluminium, mild/cast steel, 316 stainless (active/crevice), lead, silicon bronze, 316 stainless (passive), titanium/graphite — never join metals more than 2-3 positions apart without isolation.","applies":["corrosion","galvanic","material selection"],"basis":"Standard seawater galvanic series ordering used for marine material-compatibility decisions","sources":["abyc-e2","gerr-boat-strength"],"tags":["galvanic","series","corrosion"]},{"id":"isolation-bushing-dimensions","kind":"dimension","tier":2,"title":"Dielectric isolation bushing thickness","summary":"A nylon or Delrin isolation bushing between dissimilar metals (e.g. a bronze through-hull seated in an aluminium hull) runs 1-2 mm wall thickness around the fastener/tailpipe, enough to break electrical continuity without so much compliance that the joint can't be torqued tight.","applies":["isolation bushing","corrosion","aluminium hull"],"value":{"min":1,"max":2,"unit":"mm"},"basis":"Dielectric-break thickness sufficient to stop galvanic current transfer at a fastener or fitting","sources":["abyc-e2"],"tags":["isolation","bushing","corrosion"]},{"id":"clamp-bracket-bolt-pattern","kind":"fastener","tier":2,"title":"Outboard clamp/transom bracket bolt pattern","summary":"An outboard transom (jack-plate or engine) bracket bolts through the transom on 4-6 fasteners of 10-12 mm (3/8-1/2 in) diameter, arranged in a rectangle spanning most of the bracket's width so load spreads across multiple stringer/transom-core bays rather than one local bolt.","applies":["outboard","transom bracket","fastener"],"value":{"min":10,"max":12,"unit":"mm"},"basis":"Typical outboard clamp/jack-plate bracket bolt sizing scaled to engine thrust and transom-core bearing area","sources":["iso-12215-5"],"tags":["outboard","bracket","bolt-pattern"]},{"id":"steering-cable-conventions","kind":"feature","tier":2,"title":"Outboard steering cable and control conventions","summary":"Mechanical outboard steering cables (rack-and-pinion or rotary) route in a conduit with a minimum bend radius of about 200 mm to avoid binding, terminating at the tiller arm on a straight, unkinked run; throttle/shift cables follow the same rule.","applies":["steering","outboard","control cable"],"value":{"min":200,"unit":"mm"},"basis":"Common mechanical steering/control cable manufacturer minimum bend radius to avoid binding and premature wear","sources":["outboard-shaft-length-guide"],"tags":["steering","cable","outboard"]},{"id":"scupper-sizing","kind":"dimension","tier":2,"title":"Cockpit scupper drain sizing","summary":"Cockpit scuppers drain through 25-40 mm hose/tube per drain, with at least two independent drains per cockpit (so one can clog without flooding the boat) — sizing follows the same limber-hole range because a scupper is functionally a limber hole through the transom or hull side.","applies":["scupper","cockpit","drainage"],"value":{"min":25,"max":40,"unit":"mm"},"basis":"USCG 33 CFR 183 self-bailing cockpit drainage requirements plus common scupper hose sizing","sources":["uscg-33cfr183"],"tags":["scupper","cockpit","drainage"]},{"id":"stanchion-base-bolt-pattern","kind":"fastener","tier":2,"title":"Stanchion base bolt pattern","summary":"A stanchion base plate through-bolts on 2-3 fasteners of 6-8 mm (1/4-5/16 in) diameter arranged along the base's long axis (fore-aft), always onto a backing plate per this pack's cleat-backing-plate-thickness rule since lifeline loads are largely outboard/lateral.","applies":["stanchion","fastener","deck hardware"],"value":{"min":6,"max":8,"unit":"mm"},"basis":"ABYC H-40 stanchion base fastener sizing for typical lifeline side-load ratings","sources":["abyc-h40"],"tags":["stanchion","bolt-pattern","fastener"]},{"id":"through-hull-below-waterline-clearance","kind":"rule","tier":2,"title":"Minimum clearance between adjacent through-hulls","summary":"Keep through-hull penetrations ≥ 50-75 mm apart edge-to-edge below the waterline so each fitting's flange and bedding area has clear hull skin around it and a seacock handle has room to swing without hitting its neighbour.","applies":["through-hull","seacock","spacing"],"value":{"min":50,"max":75,"unit":"mm"},"basis":"Practical flange clearance and seacock-handle swing radius on a below-waterline hull penetration","sources":["abyc-h27"],"tags":["through-hull","spacing","clearance"]},{"id":"test-iso-12217-stability","kind":"test","tier":2,"title":"ISO 12217 stability and buoyancy categorization test","summary":"ISO 12217 assigns design category A-D by measured stability (righting-moment curve, downflooding angle) and buoyancy/flotation reserve — a hull or cockpit-well volume change must be re-checked against the same category's criteria.","applies":["stability","design category","hull"],"basis":"ISO 12217 parts 1-3 stability/buoyancy assessment procedures for monohulls, multihulls and canoes/kayaks","sources":["iso-12217"],"tags":["test","stability","iso12217","buoyancy"]},{"id":"test-abyc-h27-seacock-load","kind":"test","tier":2,"title":"ABYC H-27 seacock static load test","summary":"ABYC H-27 requires a seacock/through-hull assembly to hold a 500 lbf (2.2 kN) static load on the pipe/hose barb for 30 s without failing the fitting, its bolts, or the hull laminate — this drives the pack's backing-plate and flange entries.","applies":["seacock","through-hull","load test"],"value":{"value":500,"unit":"lbf","note":"held 30 s"},"basis":"ABYC H-27 seacock/through-hull static load-test requirement","sources":["abyc-h27"],"tags":["test","abyc-h27","seacock","load"]},{"id":"test-iso-9093-pressure","kind":"test","tier":2,"title":"ISO 9093 seacock/through-hull pressure test","summary":"ISO 9093 pressure-tests seacocks and through-hull bodies to at least 0.3 MPa (about 3 bar, well above any static head a hull will see) without leakage or permanent deformation, confirming wall thickness and flange-to-body joint integrity independent of the mechanical load test.","applies":["seacock","through-hull","pressure test"],"value":{"min":0.3,"unit":"MPa"},"basis":"ISO 9093 seacock and through-hull fitting hydrostatic pressure-test requirement","sources":["iso-9093"],"tags":["test","iso9093","pressure","seacock"]},{"id":"test-iso-15083-bilge-pump","kind":"test","tier":2,"title":"ISO 15083 bilge-pump system capacity test","summary":"ISO 15083 sets minimum bilge-pump capacity and hose/thru-hull sizing by boat length and compartment volume, requiring the discharge through-hull and check valve to pass rated flow without excess head loss — an undersized discharge fails this first.","applies":["bilge pump","drainage","through-hull"],"basis":"ISO 15083 bilge-pumping system capacity and discharge-fitting sizing requirements","sources":["iso-15083"],"tags":["test","iso15083","bilge","pump"]},{"id":"standard-iso-12215","kind":"standard","tier":2,"title":"ISO 12215 — small craft hull construction and scantlings","summary":"ISO 12215 (parts 1-9) governs hull, deck and structural scantlings for small craft up to 24 m: design pressures by category and speed, laminate/metal/wood scantling formulas, and bulkhead/stringer/transom design rules that this pack's thickness and spacing entries summarize.","applies":["hull","scantlings"],"basis":"Governing scantling standard for recreational and small commercial craft hull structure","sources":["iso-12215-5"],"tags":["standard","iso12215","scantlings"]},{"id":"standard-iso-12217","kind":"standard","tier":2,"title":"ISO 12217 — stability and buoyancy assessment","summary":"ISO 12217 assesses and assigns the design category (A-D) used throughout the EU Recreational Craft Directive and referenced worldwide, via stability curves, buoyancy/flotation checks and (for open craft) swamped-stability testing.","applies":["stability","design category"],"basis":"Governing standard for small-craft stability categorization","sources":["iso-12217"],"tags":["standard","iso12217","stability"]},{"id":"standard-abyc-h-series","kind":"standard","tier":2,"title":"ABYC H-series — hull and piping standards","summary":"The ABYC H-series covers hull and plumbing safety: H-27 (seacocks/through-hulls/drain plugs), H-40 (anchoring/mooring/strong points) and related standards this pack draws its fastener and load-test numbers from — what a US boat is surveyed against.","applies":["hull","plumbing","deck hardware"],"basis":"ABYC's H-series is the de facto US recreational-boat safety standard set for hull penetrations and deck hardware","sources":["abyc-h27","abyc-h40"],"tags":["standard","abyc","h-series"]},{"id":"standard-uscg-33cfr183","kind":"standard","tier":2,"title":"USCG 33 CFR 183 — Boats and Associated Equipment","summary":"33 CFR Part 183 is the US Coast Guard's federal regulation for recreational boats: flotation, ventilation, electrical, fuel and safe-loading requirements a boat sold in the US must meet regardless of any voluntary ABYC/ISO standard it also follows.","applies":["hull","safety","regulatory"],"basis":"Federal regulation governing recreational boat safety equipment and construction in US waters","sources":["uscg-33cfr183"],"tags":["standard","uscg","regulatory"]},{"id":"material-grp-eglass-polyester","kind":"material","tier":1,"title":"E-glass/polyester GRP hull laminate","summary":"The default small-craft hull laminate is E-glass woven roving/chopped-strand mat in orthophthalic or isophthalic polyester resin, ~35-45% fibre weight fraction in a hand-laid hull, density ~1.5-1.6 g/cm3 — cheaper and more water-permeable than a vinylester laminate below.","applies":["hull","grp","fiberglass hull"],"value":{"table":[{"property":"fibre-weight-fraction","min":35,"max":45,"unit":"%"},{"property":"density","value":1.55,"unit":"g/cm3"}]},"basis":"Standard E-glass/polyester hand-laid marine laminate composition and density","sources":["iso-12215-5"],"tags":["material","grp","e-glass","polyester"]},{"id":"material-grp-vinylester","kind":"material","tier":2,"title":"E-glass/vinylester GRP laminate (blister-resistant)","summary":"Vinylester resin in the outer laminate (often just the skin coat over a polyester layup) resists osmotic blistering far better than polyester at 20-40% higher resin cost — a common choice for a hull's below-waterline skin coat.","applies":["hull","grp","gelcoat blister"],"value":{"value":1.15,"unit":"g/cm3","note":"cured vinylester resin density"},"basis":"Vinylester's lower water-permeability versus polyester, standard use as a blister-resistant skin coat","sources":["iso-12215-5"],"tags":["material","grp","vinylester"]},{"id":"material-aluminium-5083-5086","kind":"material","tier":2,"title":"5083/5086 marine-grade aluminium","summary":"5083 and 5086 (H116/H321 temper) are the standard welded marine-hull aluminium alloys: ~2.66 g/cm3 density, good seawater corrosion resistance and weldability without post-weld heat treatment, yield strength around 215-230 MPa in the H116/H321 temper.","applies":["hull","aluminium hull"],"value":{"table":[{"property":"density","value":2.66,"unit":"g/cm3"},{"property":"yield","min":215,"max":230,"unit":"MPa"}]},"basis":"ASTM B928 marine-grade 5083/5086 aluminium sheet/plate mechanical and corrosion properties","sources":["astm-b928"],"tags":["material","aluminium","5083","5086"]},{"id":"material-316-stainless","kind":"material","tier":1,"title":"316 (A4) stainless steel for deck hardware","summary":"316 stainless is the default marine deck-hardware/fastener alloy: ~8.0 g/cm3 density, molybdenum-alloyed for better chloride/crevice resistance than 304, though it still corrodes in an oxygen-starved crevice without flushing or isolation.","applies":["deck hardware","fastener","stanchion"],"value":{"value":8,"unit":"g/cm3"},"basis":"ASTM A276 Type 316 stainless bar/shape density and standard marine-grade corrosion behaviour","sources":["astm-a276"],"tags":["material","316","stainless"]},{"id":"material-silicon-bronze","kind":"material","tier":2,"title":"Silicon bronze for through-hulls and fasteners","summary":"Silicon bronze (~8.5 g/cm3) resists dezincification and sits close to stainless on the galvanic series — the traditional through-hull body, seacock and fastener alloy, heavier and pricier than Marelon but rated to higher pressure/temperature.","applies":["through-hull","seacock","fastener"],"value":{"value":8.5,"unit":"g/cm3"},"basis":"ASTM B98 silicon-bronze rod/bar density and standard marine through-hull material use","sources":["astm-b98"],"tags":["material","silicon-bronze","through-hull"]},{"id":"material-hdpe-kayak","kind":"material","tier":2,"title":"Rotomoulded HDPE for kayak/dinghy hulls","summary":"Rotomoulded HDPE (~0.94-0.96 g/cm3) is the standard kayak/small-dinghy hull material: cheap, UV-stabilized grades take impact/abrasion far better than GRP at that price, but can't be structurally repaired and can creep if stored unsupported in sun.","applies":["kayak","dinghy","rotomoulded hull"],"value":{"min":0.94,"max":0.96,"unit":"g/cm3"},"basis":"Standard rotomoulding-grade HDPE resin density used for kayak and small-dinghy hulls","sources":["bs-1088"],"tags":["material","hdpe","kayak","rotomoulded"]},{"id":"material-marine-plywood-bs1088","kind":"material","tier":2,"title":"BS 1088 marine plywood","summary":"BS 1088-certified marine plywood uses WBP phenolic adhesive and gap-free veneers with no internal voids, ~0.5-0.7 g/cm3 by species — the only plywood grade for a structural bulkhead, transom core or stringer without independent lamination testing.","applies":["plywood","bulkhead","transom core"],"value":{"min":0.5,"max":0.7,"unit":"g/cm3"},"basis":"BS 1088-1 marine plywood specification: adhesive type, veneer quality and void-free construction","sources":["bs-1088"],"tags":["material","plywood","bs1088"]},{"id":"material-coosa-foam-core","kind":"material","tier":2,"title":"Coosa board and structural foam core","summary":"Coosa (fibre-reinforced polyurethane structural foam, ~0.5-0.75 g/cm3 by grade) and closed-cell PVC/SAN foam (~0.06-0.2 g/cm3) replace balsa/plywood in a cored deck or transom where rot resistance matters more than stiffness-to-weight.","applies":["cored panel","transom core","deck core"],"value":{"table":[{"core":"coosa","min":0.5,"max":0.75},{"core":"pvc-foam","min":0.06,"max":0.2}],"unit":"g/cm3"},"basis":"Manufacturer datasheet density ranges for Coosa structural composite board and closed-cell foam core grades","sources":["iso-12215-5"],"tags":["material","coosa","foam-core"]},{"id":"recipe-316-horn-cleat","kind":"recipe","tier":2,"title":"Recipe: 316 stainless horn cleat","summary":"Build a 150x40x8 mm cleat base with two 16 mm diameter x 25 mm tall horn posts unioned on, a 2 mm edge fillet, and four 8 mm bolt holes on a 120x20 mm grid clear of the horns.","applies":["cleat","horn cleat","deck hardware"],"basis":"Combines cleat-size-by-loa (150mm), stanchion/fastener-scale bolt sizing and cleat-backing-plate-thickness into one buildable cleat body","sources":["abyc-h40"],"tags":["recipe","cleat","deck-hardware"],"recipe":{"prompt":"Model a 150mm 316 stainless horn cleat: base plate with two horn posts, filleted edges, and four bolt holes","steps":[{"tool":"cad_box","args":{"dx":150,"dy":40,"dz":8},"note":"cleat base plate, 150mm per cleat-size-by-loa"},{"tool":"cad_cylinder","args":{"r":8,"h":25,"origin":[20,20,8]},"note":"horn post 1, standing on the base"},{"tool":"cad_boolean_union","args":{"of":"$0","tool":"$1"},"note":"union horn 1 onto base"},{"tool":"cad_cylinder","args":{"r":8,"h":25,"origin":[130,20,8]},"note":"horn post 2"},{"tool":"cad_boolean_union","args":{"of":"$2","tool":"$3"},"note":"union horn 2 onto base"},{"tool":"cad_hole_pattern","args":{"of":"$4","type":"drill","diameter":8,"pattern":{"kind":"grid","origin":[50,10],"dx":50,"dy":20,"nx":2,"ny":2}},"note":"four M8 through-bolt holes between the two horn posts, clear of both"},{"tool":"cad_fillet_edges","args":{"of":"$5","radius":2},"note":"2mm edge break on all convex edges"}],"expect":{"volume":57172.36,"faceCount":52,"watertight":true,"note":"measured 2026-09-19: the blanket fillet now DRESSES circular plane/cylinder rims (CADSF-1038 blendCircleBand recognition, CADSF-1098 rim pass): the R2 pass blends 36 of 48 edges where the pinned body had only the 12 prismatic box edges. 24 of the 36 are CIRCLE rims — the two horn roots ADD material (concave) and the bolt-hole mouths remove it — so the fillet step nets +727.76 mm^3 where the pin netted -884. +2.902% is the largest single move in this corpus and it is the op doing more, not the body being wrong"}}},{"id":"recipe-transom-bracket","kind":"recipe","tier":2,"title":"Recipe: outboard transom bracket plate","summary":"Build a 140x90x6 mm transom clamp-bracket plate with four 10 mm through-bolt holes on a 100x50 mm rectangle, matching the clamp-bracket-bolt-pattern entry's 10-12 mm bolt size.","applies":["outboard","transom bracket"],"basis":"Combines transom-thickness margin and clamp-bracket-bolt-pattern into one buildable bracket plate","sources":["iso-12215-5"],"tags":["recipe","transom","outboard"],"recipe":{"prompt":"Model a 140x90x6mm outboard transom bracket plate with four 10mm bolt holes on a 100x50mm rectangle","steps":[{"tool":"cad_box","args":{"dx":140,"dy":90,"dz":6},"note":"bracket plate, 6mm 316/aluminium stock"},{"tool":"cad_hole_pattern","args":{"of":"$0","type":"drill","diameter":10,"pattern":{"kind":"grid","origin":[20,20],"dx":100,"dy":50,"nx":2,"ny":2}},"note":"four 10mm through-bolt holes per clamp-bracket-bolt-pattern"}],"expect":{"volume":73715.04,"faceCount":14,"watertight":true,"note":"measured 2026-09-19: agrees with the kernel on the CADSF-1630 corpus sweep — volume inside the 0.5% band and faceCount exact"}}},{"id":"recipe-through-hull-flange","kind":"recipe","tier":2,"title":"Recipe: through-hull mounting flange","summary":"Build a 60 mm diameter x 8 mm thick through-hull flange, bore a 35 mm through-hull hole on axis, and array six 6 mm bolt holes on a 48 mm bolt circle via cad_hole_pattern circular.","applies":["through-hull","seacock","flange"],"basis":"Combines through-hull-hole-diameters (35mm) and through-hull-flange-dimensions (~1.7x tailpipe OD) into one buildable flange","sources":["iso-9093"],"tags":["recipe","through-hull","flange"],"recipe":{"prompt":"Model a through-hull flange: 60mm diameter x 8mm thick disc, 35mm bore through the middle, six 6mm bolt holes on a 48mm bolt circle","steps":[{"tool":"cad_cylinder","args":{"r":30,"h":8},"note":"flange disc, 60mm OD x 8mm thick per through-hull-flange-dimensions"},{"tool":"cad_drill_hole","args":{"of":"$0","type":"drill","diameter":35,"center":[0,0]},"note":"35mm through-hull bore per through-hull-hole-diameters"},{"tool":"cad_hole_pattern","args":{"of":"$1","type":"drill","diameter":6,"pattern":{"kind":"circular","center":[0,0],"radius":24,"count":6}},"note":"six 6mm bolt-circle holes at radius 24mm (48mm bolt circle), clear of the 35mm bore and the 60mm OD"}],"expect":{"volume":13565.4,"faceCount":18,"watertight":true,"note":"measured 2026-09-19: agrees with the kernel on the CADSF-1630 corpus sweep — volume inside the 0.5% band and faceCount exact"}}}]}