Maritime Trades and Craft Skills
What the domain tests
This domain covers measurement, layout, hand and power tools, marine materials, fastening, coatings, composites, pipefitting, welding, and electrical craft skills. It tests whether you can translate a drawing into a fit-up that tolerates the marine environment.
Core rules
- Verify the drawing revision and dimensions before layout. Check diagonal measurements for square, and account for kerf and fit-up allowance before cutting.
- Select materials for the service: aluminum, stainless steel, bronze, and composites behave differently in salt water. Avoid direct contact between dissimilar metals; use isolation pads, dielectric grease, compatible fasteners, and sealed joints to interrupt galvanic corrosion.
- Surface preparation drives coating and adhesive performance. Follow the manufacturer’s mix ratio, pot life, and cure conditions; do not apply over contamination or moisture.
- Composite repairs require tapered scarfs, clean laminates, correct resin-to-hardener ratio, and consolidation to avoid voids.
- Marine electrical work commonly uses tinned copper conductors, adhesive-lined heat shrink, support, and drip loops so water cannot track into connections.
- Welded marine structures need controlled fit-up and distortion control, not just a sound bead.
Worked example
A stainless cleat is being fastened to an aluminum deck. Direct contact creates a galvanic couple, and seawater is the electrolyte. The correct approach is to isolate the cleat with a non-conductive pad or coating, use compatible fasteners and washers, seal the joint edges, and avoid trapping water. Reasoning: the aluminum becomes the anode and corrodes preferentially; isolation breaks the electrical path and sealing limits electrolyte contact.
Traps
- Cutting before checking the revision or overall dimensions.
- Using the wrong sealant or mixing resin by eye.
- Fastening stainless directly to aluminum.
- Over-tightening fasteners into composites and crushing the laminate.