When aboard, most of our attention is devoted to the set of the sails, wind shifts and other boat traffic. We quite often don’t pay much attention to creature comforts, much to the dismay of our sailing partners. Proper ventilation of the boat is as important as having a decent set of sails. Let’s look at some possible solutions to the ventilation problem.
Sadly, many of us only use our boats on the weekends. The rest of the week they sit there, baking in the hot sun. The result is that dreaded “boat smell”. The solution is to establish a decent airflow to keep the air below as fresh as possible. It is usually impractical and unsafe to leave hatches open and unattended.
The solution to this problem that I chose was to install a pair of Nicro solar powered vents. These are powered by solar cells on top of the vent. The cells also charge a battery during daylight hours. The battery then powers the fan during night time hours. A fully charged battery will power the vent for up to 40 hours.
They are available in two sizes, 3” and 4”, and two finishes, white plastic or stainless steel. Both sizes come with two fan blades, one to push air in and one to push it out. You install the one directing the air in the way you want. Ideally, they should be installed in pairs, one near the bow with the blade to push air in and one near the stern to pull air out. This establishes an airflow that will keep the below deck air fresh in your absence.
Installation is fairly simple. Cut the appropriate size hole in your deck or hatch with a large hole saw or a saber saw. Apply sealant and screw the base in place. Then install the cover with the solar cells
Once we get to the boat, we have other options. Most of us have a bow hatch and a companionway hatch. Open those wide to take advantage of any existing breezes. Experiment with the bow hatch to determine how far you can open it under sail without fouling the jib.
If you are not under sail, you have another option to increase below deck airflow. It is called a wind scoop and comes in two different varieties. The first is a three sided fabric tube that is hoisted and kept taught with the halyard. The open side of the scoop is aligned with the prevailing breeze and captures it and directs it below.
The second type of wind scoop doesn’t require the use of a halyard. It is shaped like half a cone that sits over the bow hatch. The open end of the cone is held open by means of a flexible rod. Both types are available in marine stores for less than $75.
While all this sounds great, let’s face it, there will be nights when you are at anchor or at the dock and there are no breezes. Time for a mechanical breeze. If you are at a dock with electrical power available, you have a wide variety of 110-volt fans to choose from. On Ternabout, I had a 12” 110-volt fan I used when I was at my home dock. I could place it in the companionway, blowing in or out or place it on the galley blowing into the vee berth.
If you have a 12 volt electrical system on your boat, you have a wide variety of fans to choose from. Marine dealers and RV dealers have them in stock. Most of the 12 volt fans are permanently installed so they can be connected to the boat’s power supply. There are also battery powered fans. If you chose this option, be sure to get fans powered by “D” cell batteries for longest life.
With all this talk of ventilation options, there is one thing we haven’t discussed – pests. Depending on where you are you may encounter black flies, May flies, green flies, no-see-ums or mosquitoes. Any of which can make for less than a peaceful night’s sleep.
Some sort of screening is mandatory in these situations. There are several commercially available options for screening your companionway. Most simply drape over the opening and are held in place by weighted hems. Prices are in the range of $60 or so. In Ternabout, I used a wooden frame that fit the companionway opening. I then covered it with regular home improvement store screening held in place by wooden battens.
You can purchase off the shelf bow hatch covers that, again, simply drape over the open hatch and are held in place by a weight rope hem. The problem is you can’t use this type of bow hatch cover with a hoisted wind scoop. I solved this problem on Ternabout by taking a square of screening larger than the hatch opening and sewing a strip of Velcro along each edge. The corresponding Velcro strip was then glued to the overhead inside the boat. I would simply unroll the stored screening a stick it in place up against the overhead inside the boat, leaving the wind scoop unencumbered.
Up until this point, we have been discussing ventilating the cabin. Equally important but often overlooked is ventilation of your storage compartments. On most of our boats, these areas are closed off with covers or doors. They are prone to condensation, especially if they are next to the underwater portion of the hull. That condensation then encourages mold, mildew and rot.
I bought a collection of vents and grills from my local marine store and proceeded to install at least one in each and every storage compartment. In most cases, installation was very easy. Drill or cut the right sized hole in the compartment wall and screw the vent in place. Since these were all inside the boat and above any possible water level (unless the boat was actually sinking) so I didn’t use any sealant.
Many of our storage compartments have doors that consist of a frame with an inset plywood panel. This type of door provides absolutely to no ventilation at all. A good looking alternative is to remove that center plywood panel while retaining the outside frame, hinges and latch. Replace that plywood panel with a piece of caning. This material is used for caning chairs and is available in several styles. You want to pick the style with the maximum open space for the best ventilation. The can be stained to match the wood frame and/or varnished. I think that they also look better than the plain plywood center panels.
Often, we simply put the boat away each fall by placing a tarp or winter cover over it and waiting for spring. Proper ventilation is just as important in the winter as it is in the summer. Closed up boats tend to develop condensation and the resultant mold and mildew. Start your winter preparations by emptying everything out of the boat. Food, cushions, clothing, life jackets, etc. If it can be moved, move it off the boat and into warm storage (at least dry storage).
Wipe down the surfaces with a mild bleach solution and allow drying. Open up all storage compartments, drawers and doors. Place containers of water absorbing material such as Damp Rid or Damp Away in the cabin. Check these several times during the winter as they may fill up with water.
Provide some means for fresh air flow through the cabin. If you crack open the bow hatch or the companionway hatch, be sure to screen it to keep any critters out over the winter. Mice like to live aboard too, you know.
Finally cover the boat securely. Make sure the cover or tarp is tied securely so it doesn’t flap against the hull and mar it. If your boat is stored on jack stands, do not tie the cover to the jack stands. A strong wind catching the cover could walk the jack stands out from under the boat. If you store your boat on its trailer, consider jacking up the trailer and taking the weight off the tire. It wouldn’t hurt to cover the tires to protect them against UV exposure.
There you have it, Ventilation 101, the key to a dry, sweet smelling boat.