70 Motoryacht - Mechanicals under the Floor

[PD4077]

I am in the process of searching for a new used Hatteras MY in the 60-70 range and have inspected several already, all of which were late 1980s boats. We love the layouts, old classic lines, and of course the quality of construction these boats have. My concern on all them so far has been replacing/repairing piping and wiring run underneath the floors in the cabins/lower level. Due to the boats being 30+ years old, and the likely hood of water in the bilges over time, I am concerned with corrosion and subsequently the routing and access to these systems.

Are there line drawings of the routing of systems for these boats available? I know each boat is specific with its design drawings, but any help from the seasoned owners here would be helpful.

Before we buy, we plan to have a full survey done, a Detroit mechanic's survey and oil analysis done on the mains, and sea trials, of course.

Thanks in advance for any insight.

[jmooney]

Very little wiring is in the bilge, except for bilge pumps . The terminal strips might show corrosion, but these are easily replaced. The biggest problem is that when bilge or shower pumps are replaced , the wiring is spliced together sloppily, rather being run to the terminal strip .
Hatteras used aluminum Ardell clamps which assuredly are corroded by now . The hoses should be replaced and with new stainless steel Ardell clamps . This will require enlarging existing hatches and cutting new hatches to enable access. What you do find is that new hoses are just thrown haphazardly in the bilges and ragged holes hacked in bulkheads. But we can hope not ! Good to find a boat recommended by a forum member . As far as I know , the Hatteras schematics do not show exact wiring positions nor hose locations .

[PD4077]

Thanks Jerrie

How about fuel line piping? With the tanks being in the keel, those certainly run under the floor for some of their lengths. Do you know if there is any rhyme or reason to these? Straight down the centerline, or maybe out to the sides and then up out of the bilge?

The boats I'm looking at are all in New England so far.

[cenger]

This 77' Hatteras has been for sale in my marina in Connecticut for the past 3years. I think it would go for a good price. Looks nice but I have not been in the boat. https://www.yachtworld.com/boats/198...yacht-3547093/

[jmooney]

The fuel lines from the tanks are on top the tanks until they turn to go to the fuel manifold. There is two sets of fuel lines as you probably are aware, a supply and a return for each engine. These allow you to feed each engine from either tank . The generator fuel lines run in the port bilge until they reach the generator room . The generator fuel pickup is shorter the the engine pickup tube , so if the generator stops it might be low fuel even though the main engine is still running but not for long . Hopefully the copper fuel lines will not need replacing.

[Pascal]

I ve never seen wiring being run under the floors except for wires going to bilge pumps but all connections are high enough anyway. Most wiring is run along the hull sides and above floors

Fuel lines from the tanks are under the floors for a short distance but pretty high. I can’t imagine water level getting that high. If it does you have other issues to worry about first.

[Canuck Dennis]

On my 43 DC the fuel lines to the gen set leaked, they were run along a stringer where the water would get trapped and unless caught would be in contact at times with the lines, replaced with appvd materials.

[brettportzer]

I would say, anything higher than the stringers is pretty much unaffected by the fact that it is below decks.

Meaning, even inside the engine rooms, there is scarcely any corrosion on anything really, and the wiring and fuel lines etc are never run below the level of the engine stringers.

However, in regards to some of that, when the copper lines do get wet often, you will see corrosion there, so you will know.

We had a leak from a stanchion that made it's way behind a closet and was dripping on a copper fuel line inside an other wise literally dry and dusty compartment. And that copper was green, which is how I figured out what was happening there.

[scottinsydney]

Corrosion to fittings and wire terminals will occur if there is water in the bilge.

Salt water in the engine room bilge will evaporate leaving a nasty green corrosive film.

Also a dry bilge will reduce mould growth on woodwork and boat will smell nice and dry.

[PD4077]

Thank you all for the info in your replies. Very helpful.I am going to look at the Hatt in CT and see if it’s worth it.