How long is a boat?

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Daimon Martin.
Daimon Martin.

How do marinas calculate boat length for berths and mooring fees? As Daimon Martin explains, it’s all about LOA.

We’re responsible for looking after around 200 boats across our two marinas and ensuring they aren’t damaged is a priority. Our upgraded marinas are designed to meet the Australian Standard 3962 where possible, with adequate beam for almost all vessels. A safe haven is the main reason boaties choose a marina berth over other options.

Yesterday I had a conversation with a boat owner who was interested in taking up a berth at one of our marinas, and this highlighted a common misunderstanding that warrants discussion. The conversation went a bit like this:

Him: I’m after a berth for a 37-foot boat

Me: No problem, what’s the length overall?

The discussion about hull dimensions (generally referred to as ‘parameters’) that followed was not uncommon, not just for those of us at Batemans Bay Marina or Port Macquarie Marina. This is really about shedding light on the issue for Australia’s 347 marinas and their customers because, when it comes to marina mooring fees, many boat owners wonder why they pay for more than just the official registered length of their boat. Surely a 24-foot boat means a 24-foot berth? A 30-foot boat means a 30-foot berth?

And so on, and so forth.

Not all lengths are the same

When I studied the shipwright and boat builder trade – my first foray into the ‘salty life’ – using correct terminology was just as important as learning the skills themselves. The hull of a boat is a complex form needing specialised terms to describe it, and these parameters extend into marine drafting standards, hull form and performance, and many other facets of boating.

Establishing the length of a vessel is important when securing a registration, mooring and berth. It’s also vital to get it right for insurance. What many boat owners don’t realise is that the method for measuring length varies depending upon its purpose, so the determined length won’t always be the same – and we have a different term for each instance.

In New South Wales, where our marinas are located, NSW Maritime calculates the annual registration fee by the length of the hull alone. This is generally standard practice across Australia. The hull length is measured from the point of the bow to the transom, excluding appendages.

Marinas don’t use the official registered length to calculate the size of berth that vessels require. If they did, owners might end up with a slightly bruised and battered boat. Instead, we use a far more logical and sensible measurement – length overall (LOA) – to ensure we allocate the space required to maintain the safety and integrity of every part of a boat.

While by some definitions LOA may refer to the length of the hull alone (causing some confusion), the definition used by marinas is very specific. It is the length of the hull from the outside face of the foremost extremity to the outside face of the aft-most extremity, plus any fixed projections such as: spars, pulpits, pushpits, bowsprits, stemhead fittings, swim platforms, diving platforms, boarding platforms, outboard motors and their mounting brackets and plates, rubbing strakes, fenders, anchors and other appendages. If the projection is a removable part that can be detached without tools, it won’t form part of LOA.

This definition of LOA is consistent with the Boating Industry Association Berthing Storage and Mooring Deed – an industry standard – and the content of shipwright and boat building courses across Australia.

LOA can fluctuate after vessel maintenance, which may result in a boat no longer fitting its berth, so it’s important that owners are aware of this potential problem and provide updated measurements to marina managers.

At the end of the day, communication is key. By educating the boating community about parameters and the method for calculating boat lengths for marina berths, we can help support harmonious marina-boatie relationships as well as improve efficiencies – a win for everyone.

About the author

Daimon Martin is the general manager at Batemans Bay Marina and Port Macquarie Marina in NSW. He can be contacted on, or visit and

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