A marina pontoon specification that describes only the structure has described the cheap half. The floats and the frame are engineering, they are quoted accurately, and they rarely generate complaints. The fit-out is where the cost spread between offers actually sits and where every operational problem shows up in year two.
What follows is the list of items a berth specification has to settle, and the reason each one is a technical requirement rather than a matter of taste.
Decking: slip, temperature and what it costs to keep
Deck surface is the part of the structure people touch, and the three candidate families behave differently. Aluminium decking is light, dimensionally stable, non-combustible and recyclable, and its slip performance depends entirely on the profile and the surface treatment specified, not on the metal. Timber looks right on a traditional waterfront and brings an annual maintenance commitment plus a slip problem once algae establishes. Composite boards sit between the two on both counts.
Two properties belong in the specification rather than in the brochure. The first is a stated slip performance in the wet, since a marina deck is wet more often than not. The second is surface temperature in summer sun, which matters wherever people walk barefoot and is the complaint most likely to reach the operator.
Cleats are a structural item
A cleat is not ironmongery. It is the point at which a vessel’s mooring loads enter the structure, and those loads are continuous, cyclic and occasionally violent. The requirement is a stated pull-out capacity at a stated angle, and a fixing detail that carries the load into the frame of the pontoon rather than into the decking it happens to pass through.
The failure that results from getting this wrong is not a cleat pulling off. It is a section of deck lifting with the cleat still attached to it, which is why the fixing detail should be shown on a drawing at tender stage. Spacing matters too, and it follows from the berth layout and the design vessel rather than from a standard pitch.
Fenders and rubbing strips
Fendering absorbs the energy of a vessel arriving and protects both hulls and structure thereafter. The specification needs the design vessel and an assumed approach speed, because those two produce the energy the fender has to take, and a fender sized for small craft on a berth that receives workboats is decoration.
The detail that gets overlooked is continuity. A vessel does not always arrive square, and a rubbing strip that stops short of the corner leaves the one place most likely to be struck unprotected. Corner protection, and the fixing of it, deserves its own line.
Services inside a structure that moves
Water, power, lighting and data have to reach the berths, and routing them through a floating structure introduces two problems that do not exist on land. The first is movement: every joint flexes with wave action and with the articulation between units, so cable and pipe runs need designed flexibility at each interface rather than a length of slack.
The second is buoyancy. A service route that passes through a float compartment has compromised the watertight integrity that keeps the unit afloat after damage, so services belong in a dedicated duct that is separate from the buoyancy volumes. This is an arrangement decision made at design stage, and retrofitting services into a pontoon that was not built to take them almost always means running them on the surface, which is both a trip hazard and an eyesore.
Service pedestals then need their own consideration: fixing into the frame, drainage so the enclosure does not fill, isolation of dissimilar metals at every fastener, and a position that does not obstruct the walking line.
Safety equipment and edge treatment
Ladders at stated intervals, lifebuoys with positions marked, and an edge treatment appropriate to the users are the three items that turn a berth into a public facility. Where children or non-boating visitors have access, the edge question becomes a design decision rather than a fit-out one, because adding a barrier later changes the loads on the deck.
Lighting belongs in the same group. It is usually specified as an illumination level and rarely as a glare or spill requirement, which matters on a waterfront where the neighbours are houses and the users are arriving in the dark.
The interfaces between units
A marina is an assembly of modules, and the connections between them carry load, transmit movement and wear. Hinge or coupling type, its capacity, and whether it allows articulation in one plane or two, should be named. So should the arrangement at the shore, where a fixed abutment meets a deck that rises and falls, since that junction concentrates the relative movement of the whole installation.
These connections interact directly with the freeboard and stability figures the units are sized to, because a rigid coupling forces adjacent units to share a waterline and an articulated one does not.
Writing it so the offers are comparable
Name the decking material with a wet slip requirement. Give cleat capacity, spacing and the requirement that the fixing reaches the frame. Give the design vessel and approach speed for the fendering. State that services run in a dedicated duct outside the buoyancy compartments. Name ladder spacing and edge treatment. Name the coupling type and the shore connection arrangement.
Six lines, and they convert a tender that would otherwise be decided on the price of a deck into one decided on comparable scope. Our engineers will go through a berth layout and put these figures into the specification before it is issued, and the aluminium pontoons and landing stages we build are quoted against them rather than against a general description.