Surveyor David Pascoe reviewed two Mainships. The 350 Trawler came out reasonably; the Mainship 31 produced so many problems that he says he stopped taking notes and took photographs instead. Between them they cover the structure, the engine room and the generator.
Plywood stringers and frames
On the Mainship 31, the stringers and frames are plywood glassed over. Pascoe found about 15 holes cut through them with hole saws, leaving the plywood exposed. The whole inside of the hull had been coated, apparently to seal those edges, but spots were missed, and even where coated he found the plywood soaking up water, swelling and cracking. Limber holes cut in major frames in the forward bilges were starting to rot.
Where to look. Every hole through a stringer or frame: is the plywood edge sealed with glass and resin, or bare? Probe and meter around the holes and limbers, and look for swelling and cracks in the glass.
Water weeping through the hull
On the same boat, Pascoe found water weeping in through the hull laminate in three places, one of them on the bottom.
Where to look. With the boat hauled and drained, the inside of the hull for damp patches and drips with the bilges dry. Mark them and look for the matching spot outside.
Engine room
On the 31, the paint on both engines was bubbling and blistering from the oil pans to the risers, with black water spots that typically mean exhaust is getting into the cooling system. One intake manifold was flooded with green antifreeze, a serious cooling system leak. One cast iron manifold had heavy rust scale. The engine dipstick tubes sat 2 inches above the stuffing boxes, where water thrown by the shafts will rust them through and risk losing the engine oil.
Where to look. Engine paint and blistering, coolant level and colour, soot in the coolant, manifolds and risers for rust, and anything mounted just above the stuffing boxes.
Generator on the 350 Trawler
On the 350 Trawler, the generator was stuffed under the cockpit deck and hard to service, mounted so low that its base was getting wet and rusting badly. Its steel sound box was already suffering because the aft bilge section had no proper drainage. The bottom of that boat was beginning to blister.
Cockpit details on the 31
Pascoe found top loading cockpit lockers that fill with water, a very large engine hatch with a deep rain gutter, and a transom door with no lip at the bottom.
Recalls
The USCG recall list holds two Mainship records: the 30 Pilot and 350 Trawler, and the 34 Motor Yacht. The public pages don't give the defect; check the hull number with a dealer.
What to check on a Mainship
| Area | What to look for | Source of the concern |
|---|---|---|
| Holes in plywood stringers and frames | Bare plywood, swelling, rot at limbers | Pascoe, Mainship 31 |
| Hull laminate | Water weeping through | Pascoe, Mainship 31 |
| Engine cooling | Blistered paint, soot, antifreeze in the manifold | Pascoe, Mainship 31 |
| Dipstick tubes and fittings above stuffing boxes | Rust from shaft spray | Pascoe, Mainship 31 |
| Generator on the 350 | Low mounting, rust, aft bilge drainage | Pascoe, Mainship 350 Trawler |
| Bottom | Blisters | Pascoe, Mainship 350 Trawler |
| Recalls | Open campaigns for the hull number | USCG recall list |
Writing it up
"Main stringers, port and starboard: holes cut for wiring and plumbing with the plywood edges unsealed, wood swollen and glass cracked around three holes. Recommend the wet plywood is cut back and the holes sealed with resin and glass, and the stringers assessed for rot before purchase." List each hole by location so the yard can find them.