Bilge question

[Dutch01527]

I have a Dehler 86 Centre Cockpit. She is thankfully dry but her bilge configuration seems a bit strange to me.

In the main cabin there are no real bilges, just a central approximately 3 inch deep by 8 inch wide channel with wooden covers that give access to the keel bolts. I estimate that would hold a few of gallons of water before spilling over onto the cabin sole. No bilge pump and watertight up to about 8 inches, the height of the engine door hole ( no drain holes).

The engine is under the cockpit and has a integral manual bilge pump but no sump at a low point. I could pump water out if was about 2 inches deep across the whole engine compartment sole.

Rear cabin has no bilge, pump or drain holes that I can find. It would fill up to anout 3 feet before spilling over into the cockpit.

Is this type of set up normal?

On previous boats I have always had bilges flowing down to a low point sump and an automatic bilge pump. I wanted to replicate this and fit an sms warning alarm to text me if the bilge pump activates. I can not see any way to do this on my new boat.

 

[lpdsn]

I've a separate bilge under the engine moulded in the inner moulding. Any water that came in aft of this would end up in the engine bilge unless it were sufficient to overflow at bunk level.

Main bilge is connected with limber holes through the frames.

In your case it sounds like you'll need to fit separate bilge pumps in each area. In the grand scheme of things they're not expensive and having multiple bilge pumps will give you more pumping capacity if things get really bad.

 

[Tranona]

Quite normal - the consequences of a flat bottomed hull and a desire to have maximum headroom. how many years has it survived without having ny significant water below? On many GRP boats, electric bilge pumps die from lack of use. You can put pumps in each area but they will only be effective if you ship large amounts of water, but if you had a breach of the hull that would allow water in the pumps would be unlikely to clear it all. An alternative is to have a large capacity hand pump on a board with a hose that can be led to all parts of the boat.

Bilge pumps were essential in old boats that leaked and deep sumps to collect the water. Much less necessary on a small GRP boat that does not leak.

 

[Dutch01527]

Thanks.

My biggest concern is not a major breach, it is something like a leaking stern gland, transponder or sea cock filling the boat up when I am away from it for a few weeks. I think that a combination of a longer spare hose for the manual pump and a sms water leak detector (if I can find one) might be the way to go. I would then get warning and could ask a local mate to go down and check it out.

 

[RupertW]

Thanks.

My biggest concern is not a major breach, it is something like a leaking stern gland, transponder or sea cock filling the boat up when I am away from it for a few weeks. I think that a combination of a longer spare hose for the manual pump and a sms water leak detector (if I can find one) might be the way to go. I would then get warning and could ask a local mate to go down and check it out.

In all the boats I've owned no leak has ever caused a problem even left in the water for 5 or 6 months every year without a visit or check. I don't leave a bilge pump on as I think ruining the batteries is more likely than a flooded boat. If a boat is leaking when you are sailing then I'd want to find out why before leaving it afloat. One thing I'd be wary about is replacing a transponder with a blank before leaving as I would be replacing something I know won't leak with something I don't know.

2 of my boats have had separate shallow compartments with no drain holes between and no bilge pump. I use a turkey blaster to remove water from each one and it's fresh water condensation and rain from the mast. On another current boat there is a sump and drainage and it needs it as the sump fills often with fresh water which is partly ( or possibly completely ) from the fridge,

 

[Tranona]

Thanks.

My biggest concern is not a major breach, it is something like a leaking stern gland, transponder or sea cock filling the boat up when I am away from it for a few weeks. I think that a combination of a longer spare hose for the manual pump and a sms water leak detector (if I can find one) might be the way to go. I would then get warning and could ask a local mate to go down and check it out.

If those items are in good condition and properly maintained, there is no reason why they should leak just because you are not there. What do you think could cause them to fail?

 

[Dutch01527]

If those items are in good condition and properly maintained, there is no reason why they should leak just because you are not there. What do you think could cause them to fail?

I bought the boat in May this year and have not yet had it out of the water so I can not be sure that they are properly maintained. My intention is to keep it in the water until spring and enjoy some winter sailing. I have no reason to think that there is a problem and all seems well as far as I can see. All through hull items will all be removed, inspected / replaced in time but not immediately.

Maybe I am being over cautious but it seems prudent to have some warning if a leak occurs. It looks like I can buy a sms, 12v alarm with leak detectors sensors for c £100 ( Chinese on eBay admittedly ) so that seems to make sense to get extra piece of mind.

 

[bitbaltic]

If those items are in good condition and properly maintained, there is no reason why they should leak just because you are not there. What do you think could cause them to fail?

My Hanse 301 has a similarly shallow bilge to the OP. The heads seacock failed after a long-ish trip in may- I had inspected it and it *seemed* sound a month or two beforehand. The drip filled the shallow bilge in 24 hours. Luckily I was onboard to see it happen. Had I parked the boat up and left it for a couple of weeks it would definitely have flooded the cabin sole and caused electrical and wood work damage.

Boat has only manual pumps.

The only way to pre-emtively avoid the problem would have been to replace a perfectly dry and working seacock and skin fitting during the previous winter. Or, of course, buy a wholly new boat wrapped around them every ten years, but that is an aside

Old seacocks which appear to work well can fail quickly, and shallow-bilge modern boats are vulnerable to problems in consequence. That’s a learning and I will be more proactive with it in years from now, but for sure shallow bilges will magnify the problem more than deep bilges will.

 

[Flica]

Nearly all the "leaks" into a boat appear to be from the raw-water cooling system, water-pump, spring-loaded anti-siphon valve, water-trap or the exhaust hose.
You should thank designers for producing boats where any such leaks are immediately apparent.
But dint have carpet on the cabin sole!!
As to failing seacocks. the only one I've ever had to replace (long before any water ingress) has been the main heads seacock, always because it's been a plumbing item in brass, that de-zincifies in about 6-7 years. Now corrected by fitting a Marelon one, about twice the price but half the weight.
Though apparently French boats are notorious for failure of the inlet tap of the raw water system.