Boat taking on water vent question

[Francin728]

I have a DONZI LXR just like the one pictured. The boat has a stepped hull with 2 drain plugs one in the rear (where they normally are) and a second one under the boat at the rear of the "step" See Picture

Whenever I use the boat there is always a lot of water which comes out of the front plug upon removing it at home. there is no water coming out of the rear plug (which is not clogged) so the water has to becoming from the front side of the boat. The only possible place water could enter in from the small vent up front. See the attached picture of the same exact boat as mine. See the small vent all the way up front with the silver metal deflector cap on it? That vent is below the water while underway. Does anyone know what the vent is for? I would like to seal the vent to see if it prevents water from entering the hull however I do want to know what it is for before I try sealing it.

I went under the boat and I can not find any place where water can be coming in. I sealed around both plug housings with silicone.

 

[DuckHunterJon]

Re: Boat taking on water vent question

Hmmm, doesn't make sense to me - a vent that is below the waterline? I'd call a donzi dealer and ask them directly.

 

[Francin728]

Re: Boat taking on water vent question

Let me rephrase a little. The vent is above the waterline while sitting still. Once moving the water line then is above the vent. At slow speeds(which is the speed we move at 90% of the time) water appears to be able to rush up into the vent.

 

[Maclin]

Re: Boat taking on water vent question

I do not know what the lower hull fixture behind the step is for exactly, but the one up front and high on the keel is a drain for a cooler or just general storage compartment draining from the open bow section. The one up front should not be obstructed or plugged. If the drain plumbing to that is clogged then any water meant for that drain may be making its' way on back towards the bilge and getting trapped.

 

[Maclin]

Re: Boat taking on water vent question

Let me rephrase a little. The vent is above the waterline while sitting still. Once moving the water line then is above the vent. At slow speeds(which is the speed we move at 90% of the time) water appears to be able to rush up into the vent.

Are you saying the small drain hole up front on the keel, the one with the black arrow pointing to it in the actual pic is below the water line at some speeds?

 

[Francin728]

Re: Boat taking on water vent question

Are you saying the small drain hole up front on the keel, the one with the black arrow pointing to it in the actual pic is below the water line at some speeds?

Correct at slow speeds the vent up front with the arrow pointing to it is below the water at slow speeds. Any idea as to what it is for? This is the only place I can see where water would be entering.

 

[DuckHunterJon]

Re: Boat taking on water vent question

Something's still not adding up. If I understand correctly, that vent is above the waterline when sitting, but below the waterline when moving - boats rise out of the water at speed, not sink. I think you are saying some water splashes up to the vent when underway.

First figure out where that vent leads, and look for cracks/breaks in the lines. If it indeed is a cooler drain, and there are no breaks in the tubing, then at worst, you should end up with some water in the cooler, not in the bilge. I'd still make a call to a donzi dealer and get to the bottom of it.

 

[04fxdwgi]

Re: Boat taking on water vent question

I have a DONZI LXR just like the one pictured. The boat has a stepped hull with 2 drain plugs one in the rear (where they normally are) and a second one under the boat at the rear of the "step" See Picture View attachment 138619

Whenever I use the boat there is always a lot of water which comes out of the front plug upon removing it at home. there is no water coming out of the rear plug (which is not clogged) so the water has to becoming from the front side of the boat. The only possible place water could enter in from the small vent up front. See the attached picture of the same exact boat as mine.View attachment 138621 See the small vent all the way up front with the silver metal deflector cap on it? That vent is below the water while underway. Does anyone know what the vent is for? I would like to seal the vent to see if it prevents water from entering the hull however I do want to know what it is for before I try sealing it.

I went under the boat and I can not find any place where water can be coming in. I sealed around both plug housings with silicone.

Does that boat have an anchor locker? if so, then that would be your "anchor / chain locker" drain. Personally can't see water getting in there, especially underway, since the bow would be well clear of the water. Plus that hull, I believe, has somewhere in the neighborhood of a 20 degree dead rise and the drain would easily clear the water. If that is the chain locker drain, water backing up into it should not pose any problems if the fiberglass in the locker is in good shape. If there is a hose attached to the drain, the hose "could be no good", allowing water in.

Are there any dings in the glass lining of the chain locker from the anchor banging around in there? Rain water "could be" getting in the locker and seeping thru any holes in the fiberglass, especially if the drain is plugged up at all (which they do from the sand and debris from the anchor rhode). That drain plugging up is not an uncommom problem, holding rain water and if the fiberglass is damaged, it will seep into the boat.

I had that problem with one boat and went nuts trying to find the "leak". Re-glassed the locher and put a foam pad in there to protect the liner from the anchor rubbing / punching a hole in it again. Water leak into cuddy cabin stopped......

 

[Scott Danforth]

Re: Boat taking on water vent question

the "vent" as you call it is the standard anchor locker drain. I have never seen water come up the drain and enter a boat.

If you have a significant amount of water after use, you have a leak and you will need to find where the water is coming in.

it could be any of the following: built-in cooler drain, rub rail / cap seal, hull crack, leaking garboard plug, leaking engine cooling system.

if its a leaking plug, dont drain the boat right away on your next trip. crawl under there and dry everything off, move the boat to dry pavement, then watch for a drip. thats how I found my garboard plug leak on one of my boats.

 

[The_Kid]

Re: Boat taking on water vent question

Put a plug in the front vent and go out on the water like normal. When you're back on the trailer pull the two rear drain plugs. If you still have water coming out of the front drain, it's getting in somewhere else. If there is no water you know the water was getting in from the front vent\drain.

If that's the case there is probably a hose that came loose somewhere up front. Most likely the drain from the anchor locker was connected to it at one point and the hose either come off, or cracked.