Vented Hatch Covers

[patagoniadave]

During my RV life, we installed Max Air vent covers on the roof hatches. These allowed the hatches to stay open, even during risk of rain.

I can see where that might be an issue when sailing at sea with waves crashing over.

The only equivalent I found in a google search, is the Dorcap Hatch Vent.

I am curious about other peoples experiences with this and similar products?

 

[tfox2069]

Here's one alternative that I've purchased (at a steep discount on a West Marine sale table) but haven't installed yet. It requires you to cut a circular hole in your hatch to install, and is passive, but appears to be safe from green water over the hatch (and even if not the water intake would be very minimal). I haven't talked to anyone who has actually used this, but I do see them as standard equipment on newer boats:

 

[patagoniadave]

Here's one alternative that I've purchased (at a steep discount on a West Marine sale table) but haven't installed yet. It requires you to cut a circular hole in your hatch to install, and is passive, but appears to be safe from green water over the hatch (and even if not the water intake would be very minimal). I haven't talked to anyone who has actually used this, but I do see them as standard equipment on newer boats:

View attachment 206286

Cool, thanks, I will add that to me research list!

 

[dlochner]

There three conditions to be concerned about, sailing, moored in light to medium rain, and storms. Unless you like to have a wet V-Berth keep the fore hatch closed when sailing or motoring. Wet beds are not fun, don't ask.

In light to medium rain I like an awning that hangs from a halyard and stretches over the hatch. So long as the rain isn't driving, it will keep you dry. As a bonus on hot sunny days, the boat is cooler because of the shade.

In storms, keep it all closed.

 

[rgranger]

I think a dorade box is essentially the boat equivalent to what you had on your RV

If a wave does crash over and into the opening, presumably, it can't reach the vent hole.... and then the water can drain out the weep hole.

The airflow diagram has an error in it. If you point the opening aft, then then the air will flow over the back side of the cowel (as shown) but that will create a vacuum that pulls air out of the boat instead of pushing it into the boat as shown here.

 

[patagoniadave]

I think a dorade box is essentially the boat equivalent to what you had on your RV

If a wave does crash over and into the opening, presumably, it can't reach the vent hole.... and then the water can drain out the weep hole.

The airflow diagram has an error in it. If you point the opening aft, then then the air will flow over the back side of the cowel (as shown) but that will create a vacuum that pulls air out of the boat instead of pushing it into the boat as shown here.

View attachment 206323View attachment 206324View attachment 206325View attachment 206327

and here I thought those were wiring conduits for solar panels ;-)

I don't have any of those installed on my cabin, so it would have to be a retrofit. I like the idea though, and I could potentially install a fan at the interior. I wonder if I could put one in at least the rear hatch, or if I would come to regret it.

Thanks for the feedback!

 

[patagoniadave]

There three conditions to be concerned about, sailing, moored in light to medium rain, and storms. Unless you like to have a wet V-Berth keep the fore hatch closed when sailing or motoring. Wet beds are not fun, don't ask.

In light to medium rain I like an awning that hangs from a halyard and stretches over the hatch. So long as the rain isn't driving, it will keep you dry. As a bonus on hot sunny days, the boat is cooler because of the shade.

In storms, keep it all closed.

Yes, I learned the hard way about wet beds. I have seen sunshades on most of my neighbor boat booms. Most are made out of shade cloth, so I did not make the connection to it also bein grain protection (it almost never rains here). I am trying to mentally picture if my lazy side wants to deal with that once a week when I go sailing. I would have to make it an efficient take down, but I like the idea. Thank you!

 

[rgranger]

Okay so the schamatic diagram was bugging me so I edited it.

Here is how it should actually be set up.

Unless you are on a run, the wind should be coming over the cowel vent and not scooped into it. This will cause a vacuum on the backside and that will pull air out of the cabin. Breaking waves will also likely come from forward and the backside of the cowel will prevent the majority of the water from entering the box. What little does then drains out the weep hole and never enters your cabin (in theory)

 

[dlochner]

If rain is not a big issue, then another alternative is a Wind Scoop. A quick search will yield many results. Here's one from the SBO store.

Davis Instruments Windscoop Ventilating Sail

Davis Instruments Windscoop Ventilating Sail

shop.sailboatowners.com

 

[patagoniadave]

If rain is not a big issue, then another alternative is a Wind Scoop. A quick search will yield many results. Here's one commercial example.

Breeze Bandit Wind Scoop Hatch Wind Catcher

Breeze Bandit Wind Scoop for Hatch Air Flow while cruising, sailing, motoring boats

store.marinebeam.com

Those are cool! The problem with the fact that it only rains like 3 times a year here, is the problem with rain. I get lazy, stop checking the weather daily, leave the hatches open because of the heat, and one of these days a rainstorm is going to pop up while I am away from the boat and flood the thing.

 

[sesmith]

This works for us, unless the rain is blowing.

 

[patagoniadave]

This works for us, unless the rain is blowing.

Awesome, thanks for the photo! I was just talking to a fabric fabricator about ideas for something like that!

 

[sesmith]

My wife made that with some scraps of sunbrella she had.

 

[rgranger]

Windscoops are nice and do a good job of pushing a lot of air through the cabin (unless there is no wind). If the wind is strong enough, it also keeps the mosquitos from flying around in the cabin.

I've made my own in the past by bunjee cording a beach towel to the boathook to hold it open at the front and then attaching the back ends deck-level to the shrouds and over the open hatch (also with bungee cords). I then tied the jib halyard around the center of the boat hook and shackled it to the forestay and hoisted it a little bit.... viola... wind scoop. It worked but definitly looked hobo so your idea to fabricated from sunbrella would be better but if you just want to try it out and see if it is enough, you can make one very quickly with a few bungees, a beach towel and your boathook (or any other pole you have).

 

[seadaddler]

I have a water proof cover that covers front hatch and goes forward of hatch about 2 or 3 feet which
let’s air in and rain out and we sleep at night with no worry about rain while sleeping and keeps hot sun and heat out for us here in Florida

 

[patagoniadave]

I have a water proof cover that covers front hatch and goes forward of hatch about 2 or 3 feet which
let’s air in and rain out and we sleep at night with no worry about rain while sleeping and keeps hot sun and heat out for us here in Florida

Homemade, or did you buy it?

 

[tfox2069]

I have a water proof cover that covers front hatch and goes forward of hatch about 2 or 3 feet which
let’s air in and rain out and we sleep at night with no worry about rain while sleeping and keeps hot sun and heat out for us here in Florida

Would love to see a photo Seadaddler. I have a bunch of leftover Sunbrella from a lee cloth project and I'm trying to figure out what to do with it.

 

[dLj]

During my RV life, we installed Max Air vent covers on the roof hatches. These allowed the hatches to stay open, even during risk of rain.

I can see where that might be an issue when sailing at sea with waves crashing over.

The only equivalent I found in a google search, is the Dorcap Hatch Vent.

I am curious about other peoples experiences with this and similar products?

Maybe I missed it, but I didn't see anyone talk to the Max Air vent aspect. I've also got those vent covers in my RV. They work great - on a RV. There is no way one of those would survive ocean sailing with waves coming over them. Way too flimsy. When you are driving your RV you are supposed to close them so they don't get ripped off in the wind. they make special covers for them if you want to have them open when driving - the force of water is another level.

Not that you were thinking of going there, but I figured I'd just put it out there...

dj

 

[patagoniadave]

Maybe I missed it, but I didn't see anyone talk to the Max Air vent aspect. I've also got those vent covers in my RV. They work great - on a RV. There is no way one of those would survive ocean sailing with waves coming over them. Way too flimsy. When you are driving your RV you are supposed to close them so they don't get ripped off in the wind. they make special covers for them if you want to have them open when driving - the force of water is another level.

Not that you were thinking of going there, but I figured I'd just put it out there...

dj

I wasn't planning on using them on the boat, it was just for example of function. I did drive with them open all over the country with no issues though.

 

[dLj]

I wasn't planning on using them on the boat, it was just for example of function. I did drive with them open all over the country with no issues though.

Yeah, I've driven with them open also, but if you talk to Maxair they say you aren't supposed to. They'll sell you a special cover and then say you can... now, is that just marketing??? No idea...

dj