Limber hole from bow compartment or no?

[Hunter36Naiad]

Ahoy.

My 1980 Hunter 36 has a vast compartment under the V berth from the bow aft to a bulkhead about 1.5 ft forward of the aft end of the berth itself. As is, almost certainly from the yard, there is no drainage, no limber hole to connect this forward compartment to the bilge. If water from condensation or another source collects it just sits there.

This is not causing a major problem now. However, I'm about to build out this hold for better storage and likely a small integral tank at the aft end. In a distant future I may even want to use the space forward of the new tank as rode storage, which will involve some water.

From reading the various forums it seems many production boats (seemingly catalinas for example) often have one or more forward compartments which do not drain. Many choose to simply cut a limber hole. I could do thus, and if applicable even plum some PVC pipe under the new integral tankage.

Or, I could just leave it. If water ever becomes a problem, such as when using it for direct from deck rode storage, I could install a bilge pump for the compartment perhaps. But I need to choose and plan now before I build into this space, and certainly before building an integral tank on the hull.

My questions are these: Is there some beneficial reason that this forward V compartment is isolated from the bilge, that it is essentially a separate watertight compartment? Conversely, is this specifically bad in some way? Is it very dumb to make a second bilge requiring its own pump in the bow? Am I going to terribly regret not plumbing under this new tankage?

Would love to hear all your thoughts and opinions. Particularly if there is some basic principle of boat building and flotation that I am missing entirely.

Thanks, Greg

[Benz]

If you don't drill a limber hole and you get mud in there from the anchor chain, it will be contained, but you'll have to remove it from there (with a bilge pump, as you said). This will keep the smell from going aft, and will keep your main bilge cleaner. However, if water collects up there and the chain sits in it, that's kind of bad. If you're in a big splashy seaway and a lot of water comes down the hawse, you'll have to be sure the forward pump is working, or you'll risk overflowing the space and getting water in your cabin.
FWIW, I have a hermetic bulkhead between my huge forward locker and the cabin. It has its own bilge pump, which I rarely have to operate (it's manual), even though the hawse is open to the skies and splashes. It's just never taken on much water, even in rough seas.

[Hunter36Naiad]

Originally Posted by Benz

If you don't drill a limber hole and you get mud in there from the anchor chain, it will be contained, but you'll have to remove it from there (with a bilge pump, as you said). This will keep the smell from going aft, and will keep your main bilge cleaner. However, if water collects up there and the chain sits in it, that's kind of bad. If you're in a big splashy seaway and a lot of water comes down the hawse, you'll have to be sure the forward pump is working, or you'll risk overflowing the space and getting water in your cabin.
FWIW, I have a hermetic bulkhead between my huge forward locker and the cabin. It has its own bilge pump, which I rarely have to operate (it's manual), even though the hawse is open to the skies and splashes. It's just never taken on much water, even in rough seas.

Thanks Benz. That's one vote for keeping it sealed. Keep 'em coming.

[GordMay]

Greetings and belated welcome aboard the CF, Greg.


All interior compartments should have interconnecting limber holes, in the bilge bulkhead, to allow drainage to the bilge pump sump.
I put a short piece of S/S chain, in them, to facilitate cleaning (saw it back & forth).
The anchor/road locker should remain sealed off, from the interior, draining only to the exterior.

[steve77]

I would put in a limber hole. Sometimes water has a way of getting into places where you don’t think it can, and it’s a good idea to give it a path to the bilge sump.

I can think of no downside for putting in the hole. I think the idea of an additional pump adds complexity and thus is less desirable.

Cheers!

Steve

[tkeithlu]

One possible reason for having the compartment sealed is that it serves as a collision bulkhead. I put limber holes in both bow and steerage compartments, but added valves in both tubes so I can open them when I want to, but not before.

[flee27]

If I am understanding the sealed bulkhead situation correctly wouldn't one advantage be if the boat hit something that caused a leak. As long as the entry point of the water is below the top of the bulkhead it would contain the leaking water/minimize the amount of water allowed to enter the boat.

Saying that I agree that if water can get in under normal conditions you definitely have to have a way to get the water out.

Foster

[rslifkin]

The collision bulkhead thing doesn't necessarily mean there can't be a limber hole, but it means there shouldn't be huge ones. As in, sized so that the water that goes through the limber hole with the forward compartment severely flooded should be well within what the pumps can handle in the area it drains to.

[tkeithlu]

Or put a valve in it and get the best of both worlds.

[ArmyDaveNY]

Originally Posted by GordMay

I put a short piece of S/S chain, in them, to facilitate cleaning (saw it back & forth).

That is a good idea! Do you leave the chain in there for constant cleaning, or do you just put it in their occasionally?

If you leave it in constantly, does it create any noise, and if so, it is really an issue?
If you leave it in all the time, does it create any noticeable wear?

It is similar to running some line down the side of the hull for an hour or so when underway to scrub growth off the water line. N.B. Not when the prop is running!

[Pete7]

Originally Posted by tkeithlu

Or put a valve in it and get the best of both worlds.

My thought too reading the post. A bit of loo chain to pull through could be attached to the bung.

https://www.sailboats.co.uk/rwo-tran...r1-class-legal

[Cadence]

Originally Posted by GordMay

Greetings and belated welcome aboard the CF, Greg.


All interior compartments should have interconnecting limber holes, in the bilge bulkhead, to allow drainage to the bilge pump sump.
I put a short piece of S/S chain, in them, to facilitate cleaning (saw it back & forth).
The anchor/road locker should remain sealed off, from the interior, draining only to the exterior.

Amen!

[Hunter36Naiad]

Originally Posted by flee27

If I am understanding the sealed bulkhead situation correctly wouldn't one advantage be if the boat hit something that caused a leak. As long as the entry point of the water is below the top of the bulkhead it would contain the leaking water/minimize the amount of water allowed to enter the boat.

Saying that I agree that if water can get in under normal conditions you definitely have to have a way to get the water out.

Foster

Thanks Flee. This is definitely one of the thoughts I had and I think is replicated elsewhere in this thread. However...

Is this actually sound? I can imagine a sealed, flooded compartment being lifesaving, sure. But is it possible that it's some basic principle of boat design we're not aware of that all you incoming water should go to the keel so as not to disturb the balance? Is it possible that filling a forward compartment would pitch the bow down such that water would overtake the bulkhead causing the craft to sink at a pitch which renders the main bilge pump useless?

[Hunter36Naiad]

Originally Posted by steve77

I would put in a limber hole. Sometimes water has a way of getting into places where you don’t think it can, and it’s a good idea to give it a path to the bilge sump.

I can think of no downside for putting in the hole. I think the idea of an additional pump adds complexity and thus is less desirable.

Cheers!

Steve

Minimizing complexity is a compelling argument. Thanks Steve

[Hunter36Naiad]

Originally Posted by tkeithlu

One possible reason for having the compartment sealed is that it serves as a collision bulkhead. I put limber holes in both bow and steerage compartments, but added valves in both tubes so I can open them when I want to, but not before.

A valve! Genius! Indeed, if going with the limber hole option my plan was already to run the pvc under the new tank and all the way back to the main bilge. Adding a valve accessible there in the bilge is easy and convenient.

Strong argument here for the "best of both worlds".