Legal/documentary
- approved drawings available
- current licence/tenure
- structure dimensions match approval
- no unapproved PWC dock/boat lift/storage extension
- outstanding annual rent/fees checked
- transfer procedure confirmed
- builder and installation date
- engineering certificates
- electrical certificates
Structure
- frame straightness
- weld cracks
- corrosion/pitting
- concrete cracking/spalling
- fibreglass delamination/cracks
- timber rot/checking
- loose deck
- hidden water traps
Flotation
- list/trim
- actual freeboard measured
- water inside floats
- damaged HDPE shell
- foam saturation evidence
- access-port seals
Restraint
- pile corrosion
- pile lean
- pile-guide wear
- chain/cable wear
- anchor movement
- abnormal noises
Gangway
- hinge pins
- rollers
- bearing surface
- handrails
- low-water slope
- high-water interference
Berthing
- cleat movement
- backing structure
- fender wear
- evidence of vessel collision
Services
- RCD/electrical inspection
- shore pedestal condition
- water leaks
- cable/hose chafe
For a major purchase, commission a marine structural engineer or suitable waterfront specialist rather than relying on a general building inspection.
How to use this checklist
Inspect in a fixed order, write findings down as you go, and photograph everything. The point is not to find a reason to walk away — it is to know what you are buying and what it will cost over the next five years.
Where possible, inspect at low water as well as high water. Most of the informative evidence is below the waterline or at the transition zone that is only exposed part of the time.
Structure
- Deck: soft spots, movement underfoot, worn or missing fixings, damaged boards or panels.
- Frame: distortion, cracked welds, repairs, added members that were not part of the original design.
- Floats: damage, deformation, staining suggesting water ingress, lost buoyancy shown by uneven trim.
- Freeboard: measured at several points; uneven freeboard means uneven loading or a compromised float.
- Fasteners: missing, loose, substituted, or of a different material from the surrounding hardware.
Corrosion
- Every junction of dissimilar metals, especially stainless into aluminium.
- Crevices and clamped joints where water cannot dry.
- Anodes: present, connected, and how much remains.
- Closed sections: evidence of trapped water or no drain path.
Restraint and access
- Pile guides or rollers: wear, seizure, damage, and full movement range.
- Piles: condition at the waterline and the splash zone, where deterioration concentrates.
- Chains, shackles and connections: wear, elongation, corrosion.
- Gangway: hinge and roller condition, gradient at the current water level, transitions at both ends.
Documentation
- Approval or licence, current, and covering the structure as it now stands.
- Engineering certification and as-built drawings.
- Maintenance records, particularly anode replacement.
- Any modification, and whether it was assessed.
Interpreting what you find
- Uneven trim, movement at connections and worn restraint hardware are structural findings, not cosmetic ones.
- Missing documentation is itself a finding, and it affects value.
- A structure with visible repairs is not automatically a problem, but unrecorded repairs are.
Questions buyers ask
What findings should stop a purchase?
Evidence of lost buoyancy, cracked structural welds, seriously degraded restraint, or a structure with no approval behind it all warrant a proper engineering assessment before proceeding.
Is a professional inspection worth it?
For anything beyond a small modular platform, an inspection by someone who assesses marine structures usually costs far less than the first surprise it prevents.