How important are opening portholes?

[chris in SG]

Originally Posted by Oceansailor

Well I disagree. When you are on a swing mooring the port lights are much more efficient as the boat swings and air moves in and out on the other side.

Have a 44 foot boat with 3 large deck hatches. Two are facing fwd. If I open the port lights it is a big improvement.

Totally agree. Skipped through the discussion and surprised that, aside from general references to "circulation", nobody has really addressed the point that circulation requires the passage of air through the hull. An fwd opening deck hatch might provide a blast of fresh air in, say, 10kn+ of breeze but what if it's 5kn or less? My experience is that if you sit (or lie) under an open hatch with very little breeze, as soon as you open a portlight you will feel air movement in the hull. With only the hatch open, the hull can be a 'dead-end' for air circulation.

[Pelagic]

As I said before the problem with opening portholes.....is closing them properly when it matters!

[TrentePieds]

Hi, Jim :-)

As always, your remarks are right on the money. But you know what an old fuss-pot I am ;-)

Wolf started this thread with a question I thot, as you've deduced, was indicative of trying to deal with "the wrong problem". That happens often here, as I think you will agree. I have a preference for people knowing "the rules" before they break them, so that a breach, if one is contemplated, may be made on the basis of sound judgement. So now we've had a good discussion about the ventilation issues, and I think that may benefit many.

My comment about outside combustion air stems from that philosophy. When I was a lad in a very cold climate, it happened occasionally that people - on land - would seal their dwellings against drafts, what with fuel being expensive'n'all, and then find that their solid fuel fired stoves ("Kachelofen"), banked for the night, would consume the oxygen in the dwelling or simply emit enuff carbon monoxide to do damage.

In a boat that is far less likely to happen, of course.

There is, however, a danger that I would certainly bear in mind if I had a cabin heater running on naked flame: A propane leak from the the cooker could, in some circumstances, cause a nasty "BANG!". But we all turn off our propane on the manual valve on top of the tank soon as we've finished cooking - don't we ;-)?

As ever

TP

[JPA Cate]

I think Pelagic has the right of this one about opening port lights. If they are in the hull and ventilate guest cabins, then the host (the skipper) is still in charge of having them closed when the boat is moving.

El Pinguino's story about the HR in Drake's Channel is pretty scary. A port light is a pretty big hole to plug: There goes your favorite pillow, but for sure, then you're lucky it didn't sink you. It is why some people use storm boards.

TP, first principles aside, I think whether or not one likes opening ports depends a lot on where one is located. Sometimes we go places I perceive as "hot". At anchor, in such conditions, we'll have all three hatches open and all 14 ports, if there are guests aboard. In hot areas, people like that airflow. The cabins all have fans, too. In hot places, drying your perspiration at night helps you to sleep well. It is why I didn't write in earlier, my perception that you were trying to help someone in a cllimate you know well. Lots of people, however, live between the tropics, some of them on boats.

Cheers,

Ann

[Pelagic]

Originally Posted by JPA Cate

I think Pelagic has the right of this one about opening port lights. If they are in the hull and ventilate guest cabins, then the host (the skipper) is still in charge of having them closed when the boat is moving.

El Pinguino's story about the HR in Drake's Channel is pretty scary. A port light is a pretty big hole to plug:
Cheers,

Ann

Hi Ann, I suspect what happened in Drake's Channel, was not a failure of the fitting, but a loose clamping that allowed the dogs to slip free and possibly get damaged in the slamming.

Cabin.jpg Views: 71 Size: 93.0 KB ID: 171520" style="margin: 2px" />
My Dutch built ports are about an inch thick, with armour glass and huge pinned welded hinges and dogs.

Recessed in a box structure about 2-3 inches inside the hull line they are very protected from direct hydraulics.

The large gaskets close on a thin rimmed flange and "IF" closed properly, they are as safe as the steel hull.

Hard pressed, they are underwater without a drop coming inside.
The problem is a slightly queasy Guest, lying down in those cabin, will open against my orders, when on the high side tack.
Not thinking, they just finger tighten and forget about it to come outside and I tack.

It has happened a few times

Hence the lock nuts are now in the guest cabin, so I don't need to worry about the portholes, if they are inside the cabin.
Each cabin has its own large opening deck hatch when at anchor.

[mike62]

Hi there. Ventilation and, in some places insulation, are important issues. Honestly my advise is to research the design you want, set your buying budget, find a boat you like and can handle, buy it and turn it into all you want it to be. Get hung up on things like opening or fixed port lights and the like and you’ll never find a boat. My opinion is don’t over think everything. Find a boat you like. That’s worked for me many times.

[FuzzyFeat]

Been living aboard for decades and opening ports are a bad idea. Just another set of openings you have to close when leaving the boat in case of a rain shower. Open them and likely as not you get a splash of water along with the marginal breeze. While at anchor the fwd hatch and companionway hatch provide the ventilation, at a marina you have electricity, so why not a fan in the hatch? On my new-to-me boat, i replaced the leaking open ports/windows with dead-lights. No leaks. Lots of breeze for an aft with a fan in the fwd hatch. Fewer openings to close when the 4 AM rain showers come.

[Sailorbob8599]

Originally Posted by FuzzyFeat

i replaced the leaking open ports/windows with dead-lights.

Fuzzy, having done this, do you now need to keep the cabin lights illuminated continuously while aboard? ...

[Seaworthy Goods]

Opening portholes are invaluable to get ventilation for the comfort of people plus a reduction of stale air that fosters mold and mildew.

We are former sailors who wanted to solve some of the problems discussed in all these posts. Many came up when we cruised several decades ago in FL and the Bahamas. Using our plastics business provided the perfect opportunity.

So we designed, manufacture, and sell 2 products that address the main drawbacks of opening portholes -- lack of ventilation during rainy weather and condensation drips.

One product is a rain shield that goes over the porthole and the other is a water trap that catches drips on the inside.

We invite you to visit our Seaworthy Goods website to learn more about them.

[FuzzyFeat]

By dead-lights are non-opening windows. Plenty of light below.

[El Pinguino]

I am both amazed and bemused that no-one has mentioned using a windsail or scoop for serious tropical ventilation thus far... this sort of thing ..


https://www.ebay.com/itm/AIR-SCOOP-H...-/161836556720

[TrentePieds]

Too obvious or too old-fashioned - I dunno which ;-)

TP

[Nicholson58]

Originally Posted by Lonewolf

Hi there,

My search for a boat is on going and I'm trying to determine how important opening portholes should be as a liveaboard.

I'm aware that condensation/moisture build up is a serious matter on boats and I'm placing a high priority on minimizing this. The first things I'll be doing is lining the hull with insulation and installing a diesel heater if it does not have one.

I'm curious about ventilation recently as I see a lot of boats for sale that have very few opening ports, if any at all, just the opening hatches. I cant seem to find any answers on this topic so far. My gut feeling is that it's probably a big deal, just looking for some first hand experience to confirm or deny my suspicions. How much value should I be putting into opening portholes?

We live aboard in the Caribbean. It rains regularly here so we rarely open any side Ports. The scramble to shut them all is too intense. I do open the one over the engine for cooling. Main top hatches provide all ventilation.

[Kiwi.]

Originally Posted by Lonewolf

Hi there,

My search for a boat is on going and I'm trying to determine how important opening portholes should be as a liveaboard.

I'm aware that condensation/moisture build up is a serious matter on boats and I'm placing a high priority on minimizing this. The first things I'll be doing is lining the hull with insulation and installing a diesel heater if it does not have one.

I'm curious about ventilation recently as I see a lot of boats for sale that have very few opening ports, if any at all, just the opening hatches. I cant seem to find any answers on this topic so far. My gut feeling is that it's probably a big deal, just looking for some first hand experience to confirm or deny my suspicions. How much value should I be putting into opening portholes?

When cruising down here (we're in Mooloolaba in Queensland) we log on to the forum in the evening and so are very late to comment. This is now 5 pages long! So very important; it is normally only two pages by the time it gets to us.
My Commodore's input (she who must be obeyed) is that any opening less than six feet (1.8 metres) away from the water, must not open, she's measuring up plus horizontaly. So hull portholes in any boat less than 60 feet (18 metres) would never qualify. Her issue is the salt that comes with the air; the higher the air input, the less the salt. Salt encrusted bedding is uncomfortable, salt encrusted machinery can sink the ship. (Funnily, my standards for offshore racing boats were similar for very different reasons.)
Even with low level portholes we have always preferred hatch scoops and other ways of letting (as dry and salt free as possible) air into and out of the boat.
So no value in opening portholes in any boat under 60 feet.

[KJB]

My personal preference is to have opening ports. On our boat, we have 14. As well as two stern windows, a butterfly hatch and 3 top hatches. Living in the SF Bay there are times when it is nice to have many of them open. Our cockpit hatch stays open almost continually.

I really do think it is weather and location dependent though. We don't have problems keeping the boat warm when needed, although our ports are bronze, and they do collect condensation. To be fair, although our boat is fairly new (1980) by wooden boat standards (strip plank construction), her design is very old-school. I even have pin-rails, which I love.

At the end of the day, I suppose it depends on your personal design tastes, and intended usage. Many modern sailboats don't seem to come with many.