Catalina 400 Mk Ii Known Issues

The holding tank and associated plumbing on the Catalina 400 MkII is located within the hull liner cavity in the aft cabin area, making inspection and replacement extremely difficult. Check for odor permeation in the hoses (which indicates aged sanitation hose) and verify the tank vent and deck pumpout fitting are functional.

Catalina's factory wiring on this era of boats frequently used undersized wire runs and crimped, non-tinned connectors in damp bilge areas, leading to high resistance connections, corrosion, and occasional chafe failures. A full electrical inspection tracing each circuit is strongly recommended.

Early Catalina 400 MkII boats were fitted with the Universal M-35B or M-40B diesel, and later ones with the Yanmar 4JH series. The engine compartment is relatively tight and the raw water impeller housing and heat exchanger are difficult to access, leading to deferred maintenance and overheating problems. Confirm full service history and check for evidence of overheating.

The large opening ports in the hull sides (a distinctive feature of the 400 series) are known to develop leaks at their frames as the sealant ages and the aluminum frames oxidize. Water intrusion can wet the hull liner and lead to hidden moisture accumulation in the cabin side laminate.

The molded-in hull liner system used by Catalina creates dead spaces between the liner and hull that trap moisture and are essentially impossible to inspect visually. Moisture meter readings across the bilge and under-berth areas are essential, as saturation can go undetected for years.

The anchor locker on the foredeck is not fully drained and sealed from the interior, and water can migrate below into the forward cabin area. Check for staining, soft balsa core, or moisture around the forepeak bulkhead.

The Catalina 400 MkII uses an in-mast furling mainsail as standard equipment, and the Isomat or Selden in-mast furling systems fitted to these boats are known to jam or furl poorly if the mainsail luff tape stretches or if the foil extrusion warps slightly. Inspect the extrusion for straightness and verify smooth operation through full range.

The mast step sits on the keel centerline on a compression post, but the base of the compression post connects to the hull-liner structure rather than directly to the keel floors. Inspect around the mast base and compression post foot for cracking or movement in the liner.