Widening Structural Doorways Beside a Chainplate — and a Watertight Forward Hatch

Two genuinely different projects came together this week: a new watertight hatch for the bow, and a structural modification most people shouldn’t attempt without a proper engineering background — widening doorways immediately next to a chainplate-bearing bulkhead.

A Watertight Forward Hatch, Built Like the Floors

The new hatch going into the very front of Harry’s room replaces what was there before — a scrap of perspex that had itself replaced a bit of plywood, both makeshift compared to what’s going in now. It’s built the same way as the recent floor panels: PVC foam, infused, with a flange integrated directly into the layup rather than bolted on afterward.

The flange sits on the water-pressure side of what’s now a properly watertight forward bulkhead, mating against a moulded surface laminated onto the bulkhead itself, with a rubber seal between the two. The design logic is the same as the semi-watertight engine room door covered in an earlier post: the more water pressure that builds against it, the harder it presses the seal shut rather than pushing it open. If water ever gets high enough to reach this hatch, the last thing you want is pressure working against the seal rather than for it. A bung at the base is the only other way in or out of that compartment — genuinely watertight, not just water-resistant.

The hardware finishing it off is 3D printed: an offset scribe tool for marking it up, and small hatch dogs — the little locking pieces that hold it shut — printed and fitted into place with cardboard packing to get the alignment right before gluing. Since all the load in a flooding scenario is pushing the hatch further into its seal rather than out, the dogs only need to hold the hatch in position, not resist real force themselves.

What’s Coming: Solving the Existing Hatch Problem

While that new hatch goes in at the bow, there’s a separate, older hatch nearby that’s causing genuine headaches — it leaks badly and doesn’t seal properly, and it’s held in with a ring of bolt holes that feels like a step backward now that every other bolt hole on this side of the boat has been eliminated. The plan is either sourcing proper spare parts or replacing it outright, and rethinking its position while at it — directly over Harry’s bed gets uncomfortably hot in summer, so an inboard-side hatch that doubles as an escape hatch is the leading option instead.

Widening the Doorways Beside the Chainplate

The bigger structural job this week: widening the doorways either side of a bulkhead that carries real rig load — this is the same bulkhead the chainplate ties into, so cutting into it isn’t something to approach casually.

The process started with easing rig tension off entirely before any cutting began, since that bulkhead is directly carrying the rig’s load. Both sides were marked out and cut at the same time, opening up genuine walk-through clearance where there wasn’t any before. Once the new unidirectional fibre reinforcement was laminated in and edge-capped, and fully cured, rig tension went back on — the structural side of that job done, with the same treatment still to come on the inboard side, where furniture needs pulling clear first to get proper access.

A clear note on this one: this isn’t a project to copy without the right background. Cutting into a bulkhead that carries rig tension, without understanding load paths and how to properly reinforce what you’ve removed — the same principle covered in detail in penetrating a bulkhead correctly — is exactly the kind of modification that needs a composites engineer’s judgement, not enthusiasm alone. Even with decades of professional experience across race boats and grand prix composite work, this kind of change still occasionally gets run past other experienced engineers as a second opinion before cutting. If your background isn’t in composites and structural engineering, the right move is finding someone whose is, not learning as you go on a load-bearing bulkhead. The upside of a boat built in composite is real — it can be cut, modified, and glued back together stronger than before, which is exactly what’s happening here — but that upside only holds if the person doing the cutting actually understands what they’re changing.

What Paikea’s Trim Reveals About Her Design History

A side observation worth sharing: checking a boat’s level or trim comes down to checking the bulkheads, since a boat is built with its bulkheads set vertical while the hull itself sits level on the ground during construction. Right now, Paikea’s bulkheads sit within 0.2 of a degree of vertical — genuinely close to level fore-and-aft, even though she visibly sits bow-up and stern-heavy at the moment, since the wing deck runs at its own angle relative to the bulkheads.

That nose-heavy characteristic likely traces back to her design history — Paikea began life smaller than her current 42 feet, extended up through intermediate lengths before reaching this size, and stretches like that tend to leave the mast sitting further forward than a boat designed at that length from scratch would have it. Extending a hull’s length after the fact usually throws off the original waterlines and volume calculations to some degree, and it shows in details like this one.

In This Series:

Follow the rest of Paikea’s interior transformation on the Paikea’s Refit page.