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On Powerboats - Hatches, windows and air conditioning

Cabin lighting — natural and electric — and a comfortable environment below help a boat’s livability

Cabin lighting — natural and electric — and a comfortable environment below help a boat’s livability

Last month we started to look at powerboat accommodations, considering how the companionway and stair design, headroom, berth size and midcabin accessibility affect a boat’s livability. Also, how the too-fat, too-flat hulls that produce very large cabins also pound mercilessly in the most benign sea conditions. Any boat represents a lot of compromise; the trick is to determine if a particular boat is compromised in a way that suits you.

This month let’s consider a few other accommodation elements, including cabin lighting (both electrical and the free kind from the sun), window size and location, overhead hatch size and accessibility, and air conditioning.

Electrical lighting

The amount of electrical lighting your cabin needs is dependent on the size of each space (saloon, stateroom, head, midcabin, etc.); the décor, especially the color of the bulkheads, overhead and deck or sole; and the use the space is put to, whether reading, cooking or brushing your teeth.

On many boats the only time you can really test cabin lighting, of course, is at night. But it’s important to know how well-lit cabin and staterooms will be in advance, so do as much checking around as you can, at least closing the companionway door and any window or hatch blinds to get an idea as to lighting adequacy. Overhead lighting should brighten up the entire space evenly.

Also, check the reading lights for the berths and settees; ideally, they are adjustable so you can point them where they’re needed. Rheostats are nice to have, allowing you to adjust the intensity of lights to suit the occasion and the mood. The galley should have its own lighting, both overhead and indirect in the counter area. Courtesy lighting just above deck level provides just enough illumination to allow you to find your way around the boat at night, like a night light at home. Switches should be logically situated at the entrance to each space.

Sunlight and windows

It seems that a trend — and it’s a welcome one — for more natural light, with bigger windows to let sunlight in, is slowly gaining momentum among cruising boats. Many boats are still designed with no portlights or windows of any kind in the hull sides, and they are like caves inside. As long as their boats sell, however, builders don’t have a problem with this because it’s much easier, cheaper and faster to build a boat without windows. But the effect can be gloomy, the only light coming from an overhead hatch or two and whatever sunlight makes its way down the companionway.

The main reason the pendulum shifted from lots of glass through the 1970s to cave-like, windowless cabins in the ’80s and ’90s was that the windows leaked, and they were too much trouble for builders to deal with. For instance, Bertram, Hatteras and Viking all built their convertibles with glass windshields in the 1960s and ’70s but wound up glassing them over due to persistent leaking problems. Then the builders — and their customers — found out they now had room for lots of cabinetry, drawers, oversized televisions and home-size side-by-side refrigerators by using the space below where the windshield used to be.

Thankfully, more express cruiser builders are fitting their boats with bigger windows up high in the trunk cabin sides and more of them. They’re also putting larger windows in the hull sides that afford a good view of the proceedings outside from the galley or saloon. No one wants to peel carrots while staring at the inside of the boat when they could be watching the scenery going by. These bigger windows not only improve the view, they let in a fresh sea breeze — at least the kind of windows that open.

While leaks used to be an issue, aluminum-framed window systems, which are screwed and glued into place, and frameless glass windows have changed everything for the boatbuilder and boat owner. The aluminum-framed windows open, letting in fresh air, and they have integral gutter systems that drain overboard. The frameless glass windows are fixed, bonded to rabbets in the hull or deckhouse opening. They don’t leak or corrode, and they even add to the stiffness of the superstructure.

Overhead hatches

Overhead hatches let sunlight and fresh air in just like opening side windows do, but they also serve another useful function: They are a way out in an emergency. In fact, the American Boat and Yacht Council, whose recommendations U.S. boatbuilders are supposed to follow, specifies that an alternate means of exit be built into the boat.

Imagine you’re woken by smoke pouring out of the engine room or by a definite and increasing aft-oriented deck angle — a good sign that the boat is quickly sinking at the stern. At this point, you’d likely be looking for another way off the boat than through the companionway.

The ABYC states that “enclosed accommodation spaces shall have a second readily accessible means of exit if one exit can be blocked by a fire in a galley or machinery area.” It also specifies that the exit should be at least 14.5 by 18.5 inches, 270 square inches (a 16.4-inch square), or 18.5 inches in diameter. In real life these dimensions are much too small, given the expanding size of Americans. I’d look for a boat with a hatch that’s at least 20 inches across — better yet, 24 inches. You may be happy with a smaller hatch, but make sure you and your likely guests will be able to exit in an emergency.

Also, make sure you can get to it. The best location for an escape hatch in the average cruiser is above the forward berth, so make sure you can climb up on the berth and out the hatch. Some have a fold-down ladder attached to the overhead that’s used to climb out of the hatch.

Overhead hatches that face forward when open force copious amounts of fresh air into the cabin while under way. Hatches that face aft when open will draw air out with a vacuum created by the venturi effect. A great combination is a forward-facing hatch above the saloon or forward stateroom and an aft-facing hatch in the head.

Air conditioning

Many boats come with air conditioning these days, or at least the builder offers it as an option. Let’s look at three considerations that determine how successful an air conditioning system is on a boat: BTU capacity, diffusion and noise.

The A/C system’s BTU rating refers to its capacity to produce cooled air. The cooling capacity needed is dependent upon a number of things, including the volume of the accommodations and whether the hull and deck structure are insulated. The latter mostly comes down to whether the hull and superstructure are cored with foam or balsa (which acts as an insulator) or solid fiberglass (which doesn’t), and how much cooled air is allowed to escape through cracks and crevices and other openings between the accommodations and the outside of the boat.

A cored hull and superstructure, along with light-colored topsides, are much easier to cool than a solid-glass, dark-topside boat. Ideally, you should be able to run the boat you’re considering buying — or at least be on board — on a hot day to see if the air conditioning is up to the task of keeping the accommodations cool. A boat that lives in Maine in the summer is obviously going to require a lot less BTU capacity than one that summers in Florida.

Beyond BTU capacity, look for even diffusion of cold air; the last thing you want are ice-cold spots here and hot spots there. The way the air is delivered and dispersed throughout the cabin is important, and the best designs use louvered vents that direct the chilled airflow over a wide area, not directly where people sit or congregate.

Some boats have A/C units situated throughout the boat. The forward stateroom may have its own unit under the berth, the one in the saloon under the dinette, and so on. This arrangement minimizes plumbing but also has the potential to maximize noise levels from the compressors — for example, when the unit is located under the master stateroom berth. Some builders put the A/C compressors in the engine room to isolate the noise from the accommodations; chilled water is then piped to air handlers throughout the cabin. Whatever the design, make sure the noise levels are acceptable, especially in staterooms, and that the airflow is both diffused and adequate for comfort in the areas in which you’ll be operating.

Eric Sorensen was the founding director of the J.D. Power and Associates marine practice and is the author of “Sorensen’s Guide to Powerboats: How to Evaluate Design, Construction and Performance.” A longtime licensed captain, he has spent 40 years operating charter and commercial fishing boats, Coast Guard vessels, and Navy ships and patrol boats. He can be reached, and his book purchased, at .