Altamira – Building the missing aft cabin bulkhead

Altamira is a Marine Trader double cabin trawler, 38 feet LOA, built in Taiwan ROC in 1988. We bought the boat from the original owner in 2007. The boat has some window and deck rain water leaks that I consider typical for her age and construction, but generally, quality is good, construction is suitable, and systems are adequate and reliable for use in her home waters, the Chesapeake Bay and tributaries.

Over the years of ownership of any boat, questions about why this looks like this, or that works like that, will arise. Sooner or later, most of these questions are answered. This post asks one such question in two parts, provides the answer, and describes what was done to correct the structural problem that the answer revealed.

The double cabin configuration of these boats provides a second private cabin with private toilet, sink, and shower/tub, at the expense of open space in the cockpit aft at the transom. The designer/builder must balance the space needed for the berth in the aft cabin against the space needed for a practical cockpit aft of the cabin, on the deck, at the transom. Not an easy task on a boat 38 feet LOA, because a structural component (bulkhead) would be built at the aft end of the aft cabin. This bulkhead should extend all the way across the hull, would rest on the hull bottom longitudinal (fore and aft) stringers and chine logs below, and is intended to support the substantial weight of most of the aft cabin, aft side decks, and the cockpit deck.

On this Marine Trader, either the designer or the builder chose to extend the aft cabin centerline berth into the space aft of the aft cabin, through the expected location of the bulkhead. As well, the aft cabin counter and cabinet fixtures are configured so as to encroach on the bulkhead space. The build was completed and the fit and finish of the aft cabin elements is fine, but the bulkhead is not present. This means that the substantial weight of most of the aft cabin, aft side decks, and the cockpit deck is (and has been since construction 1988) supported only at the hull sides, a span of over 12 feet.

On to the question(s) and the answer. Why do the cockpit hatch gutters not drain into the drain tubes provided at the transom and overboard, instead, always overflow into the lazarette? Why does rainwater always pool on the side decks at the rear of the aft cabin, instead of flowing off and through the port and starboard relieving ports? Because, without the support of the missing bulkhead, over the years, the rear of the aft cabin, the side decks and the cockpit have sagged downward considerably under their own weight. The forward sections of the cockpit hatch gutters are lower than the aft sections with the drain tubes. The inside edges of the aft side decks are lower than the outsides. The extent of damage to other core and deck components is not known at this time. In fact, the entire cockpit front (at the join to the aft cabin) can be seen to be lower than the cockpit rear (at the transom).

I am beginning the rework of the aft cabin and construction of the missing bulkhead and I will post photos and descriptions as the work continues this winter.

Starboard side deck at aft cabin showing standing rainwater
Starboard side deck at aft cabin showing standing water.

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