Boat Door Design: What a Gunboat 68 Gets Right
A question that comes up often enough to deserve a proper answer: is it normal for your catamaran’s doors and lockers to jam shut while sailing? No. Not on a well-built boat, and it shouldn’t be accepted as normal on any boat — even a soft, mass-production one.
Testing it in real conditions
The clearest way to answer this properly is to show it, not just say it — in a genuinely rough beam-on seaway, exactly the kind of sea state that puts the most twisting load through a catamaran’s structure, filming from inside during a full-loaded delivery in less-than-ideal conditions. There’s some creaking and groaning audible, some internal liners shifting slightly — the normal sound of a boat working through real seas. That’s expected. What isn’t happening is the furniture rattling loose or the structure flexing enough to affect anything functional.
The test that actually matters: closing a door in exactly these conditions — full load, worst twisting the boat sees underway — and watching whether it holds shut or flies back open under hull flex. It holds. Both doors, tested the same way, hold the same way.
Where the line actually sits
Every boat flexes to some degree — that’s simply how a composite hull works under load, and it’s not something to be alarmed by on its own. The distinction that matters is whether that flex stays within what the structure was actually engineered to handle, or whether it’s excessive enough to compromise basic functionality — doors jamming, lockers popping open, fittings working loose. A well-engineered hull keeps that flex contained enough that none of that happens, even in genuinely demanding conditions. If a boat’s doors won’t open reliably underway, that’s not something inherent to catamarans as a type — it’s a sign the structure wasn’t built stiff enough for the loads it’s actually seeing.