Not sure what you mean by 'under the forward part'. Can you be more specific? Under what conditions? For example, does the V-berth get wet after a sunny motoring on a fair, calm day? Or does it get wet after a rough ride in challenging seas when lots of spray or green water is coming over the bow?

More info will help us to help you.

Our bulkhead at the forepeak got wet, too, and I traced it to water coming in from the anchor windlass. It has always been after using the boat and taking water over the bow. I doubt that rain could get in that way.

It may not be a great solution, but I stapled heavy pastic to the side of the teak bulkead that faces the anchor windlass so that any water that hits there will fall to the bilge without soaking the wood.

I think what you're describing is indeed condensation, mostly moisture that you have exhaled.

I would guess that the problem is rampant when outside air temperatures are coldest, but that it still exists even in summer because the surrounding water is cold year round. If no one is staying on the boat then the problem doesn't occur, right?

[QUOTE=deising;7584]Our bulkhead at the forepeak got wet, too, and I traced it to water coming in from the anchor windlass. It has always been after using the boat and taking water over the bow. I doubt that rain could get in that way.
[/QUOTE]

Is it possible that the water leak from the windlass is actually from the foot switch? That's where I had a leak from, and it's an extremely easy fix.

I'm pretty sure what you're describing is condensation from exhaled breath. Here are a couple ideas to think about.

If you have the Catalina inner-spring mattress with the two halves hinged together, as we have, you might lift - kinda 'fold up' - the mattress in a V shape each morning, or maybe every second morning to let everything air out. When leaving the boat for several days or longer, we always leave it 'folded up'. In the winter months we remove the mattresses entirely and keep them at home.

If your mattress isn't easily 'folded up' in that manner, consider lifting it each morning and placing a spacer of some type, say an empty coffee can, beneath to allow air flow.

For live aboards, I would suggest some kind of dehumidifier.

Another idea for live-aboard use might be installing a small, low-energy (100 watt?) heater mounted in one of the under-V-berth drawer openings that would slightly warm that area and keep the air circulating. (If you decide to do this please photograph the process and do a writeup for JibSheet, won't you?

Managing this condensation is essential for keeping mildew in check in our colder water region.

My wife and I were anchored out one cold fall night. I decided that having the forward cabin door shut while we slept, would help trap our body heat and keep us warmer. Not sure if it did that, but it sure trapped the moisture in our breath. It was actually raining in the forward cabin. The entire overhead was covered with drops just waiting to fall. Wiping it all off soaked a large towel. Never did that again.

Condensation is definitely a factor. We were out over the New Years weekend with nightime temps near 54F and we had lots of condensation raining down on us by morning.

I just figure I don't need to wash my face that following morning.

Larry had suggested to pickup a dehumidifier for the summer. I just purchased a humidifier for our boat last week at Walgreens. They sell this nifty little humidifier that is perfect of rour boats during the winter months. You use a 20 oz. size bottle (you can use a bottled water bottle) and it creates enough humidity for your comfort. Works slick!

Actually, Glenn, my suggestion of a de-humidifier was primarily for the winter months - not really for full time de-humidifying - for a liveaboard in an area with cold water, like the Pacific Coast. These are the conditions in which we on the left coast experience condensation.

My other idea of a small heater and circulating fan installed beneath the V-berth in lieu of one of the drawers actually has more appeal to me. That might be the simplest, lowest cost, and most effective solution. I don't know if anybody has attempted it, but I'd be willing to experiment if I were a liveaboard.

A few years ago I had a consulting job up north where I stayed on my boat, Mondays thru Thursdays, through a cold winter. Condensation was a terrible problem. Of course, moisture is the genesis of mildew, so it must be kept under control. A forced air furnace is the first and best defense against the problem in the rest of the boat as it circulates warm dry air throughout the main part of the boat, but the berth condensation requires a special approach.

Dri Deck Tiles under cushions are good air spacers. A 1/4 inch lath spacer under the forward lip of the V berth hatch is keeping the air moving while keeping out rain and intruders. Good luck!

[quote=deising;7600]Condensation is definitely a factor. We were out over the New Years weekend with nightime temps near 54F and we had lots of condensation raining down on us by morning.

I just figure I don't need to wash my face that following morning.[/quote]

Duane is definitely a glass half full person!

But seriously, just wondering what role would added heat play in this? Like if you had a vented cabin heater or electric heat running does that change things even if you only raised the temp by say 10 degrees? I think it would but don't fully understand the science of what is happening.

Air can contain a certain amount of water in the form of water vapor depending upon its temperature.

Condensation occurs when the air is cooled lower than the 'dew point' of the air under its current condition. Let's say the cabin air is at 60F and has a fair amount of water vapor in it, but not quite the maximum it can hold at that temperature. The dew point might be 55F for that air. As the temperature drops to 55F, the air finally reaches its saturation point. If the temperature continues to drop, some of the water vapor has to condense into liquid water. The lower the temperature drops, the more moisture has to come out.

In the case of the v-berth condensation, you are exhaling warm, moist air with every breath and this air rises to meet the relatively cold hatch cover and framing. As that air cools from contact with the hatch, that air has to condense out some of the moisture and it appears as droplets that gravity eventually puts back onto your head and berth cushions. That is what is known as a viscious cyle. :D