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On Powerboats - The compromise of ride vs. cabin size - Soundings Online

On Powerboats - The compromise of ride vs. cabin size

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Look for accommodations that are comfortable for overnighting but not at the expense of the ride

Look for accommodations that are comfortable for overnighting but not at the expense of the ride

With the variety of cruising powerboats plying the waters these days, you’d think there would be clear agreement and standards for designing their accommodations. For better or worse, this is not the case.

Of course, the Coast Guard, through the Code of Federal Regulations, has a lot to say about safety requirements, including ventilation for boats with gasoline engines. There also are plenty of American Boat and Yacht Council standards and recommendations that deal with preventing carbon monoxide accumulation, galley stoves and other cooking appliances, firefighting equipment, compressed natural gas systems, etc. But these organizations clearly are focused on safety, not passenger comfort and convenience.

The question is, what good is a cabin boat if it’s not comfortable to be on board overnight? What I’ll do here is go through an imaginary boat tour, consider some of the compromises a designer has to make, and help you judge — when shopping for your next boat — whether those compromises were made in a way that serves your interests.

The companionway

Walking down a set of stairs into the cabin typically is the first accommodations-related design element you’ll encounter on a boat, and you’ll find quite a range in the width of the companionway from one boat to the next. A lot of this relates to the size of the boat, especially its beam, and to the priorities placed on the space available at the aft cabin bulkhead. Competing interests include the size of the molded port-side passenger seat, which on some express cruisers also provides access to the midcabin below; the width of the centerline molded steps leading to the foredeck; and the size of the helm station to starboard.

The range of companionway widths I’ve seen varies from around 18 to 25 inches. A boat with a 23- or 24-inch companionway is very comfortable, and 21 or 22 inches is still manageable. Get much narrower than 20 inches, however, and things start getting noticeably tight. While narrower entrances on 24- to 26-footers can perhaps be accepted or overlooked, given the constraints of an 8-foot, 6-inch beam, be aware of the issue when comparison shopping. Which builders are setting the standard among larger boats? One is Sabre Yachts; the 42 Hardtop Express I was aboard a few weeks ago had a 25-inch-wide companionway.

Stairs

Descending the cabin stairs on a boat is seldom as easy as it is at home, where building-code standards commonly call for a rise of about 7 inches and a run of 11 inches. Since the total rise (the vertical distance from the pilothouse or bridge deck to the cabin sole) on a typical boat can be 3 to 5 feet or more, there simply isn’t room for much run (the horizontal distance the stairs take up). You’d lose too much cabin space following the house formula for boat stairs. This means that the ratio between rise and run on a boat often is nearly reversed from what it is in a house, with greater rise than run. In fact, an 8- or 9-inch rise and 7- or 8-inch run isn’t uncommon on pleasure boats, and it’s a compromise between the ease of home stairs and the most effective use of space on a boat.

Whatever the rise/run ratio, the rise in each step should be the same — no more than 9 inches is preferable — from the sill at the top to the deck at the bottom. Otherwise, you have a tripping hazard, since people naturally expect stairs to be even. If you check out a boat that has a first step with a 10- or 11-inch rise and the rest of the steps have an 8-inch rise, the builder could, and should, have done a better job evening things out.

Headroom

Whether you’re on a boat, in a house or on a plane, the amount of headroom has a big impact on the feeling of spaciousness. The higher the overhead, the bigger the cabin feels, at least up to a point. Boats are limited by center-of-gravity and aesthetic considerations — you don’t want your cruiser to be top heavy or look like a motor home — so headroom has a ripple effect during the design process.

Typically, a well-designed 26-foot express cruiser, say a Regal or Sea Ray, will have around 72 inches of headroom at the companionway, and it goes downhill from there as you move forward in the cabin, following the slope or pitch of the cabin top above. On a 32-footer, there’s typically up to around 74 or 75 inches of headroom aft in the cabin, and by the time you get to 40 feet, most boats have 76 inches or more. Some notable good examples in the cabin headroom department include the Chaparral 310, at 78 inches; Regal 4460, at 80 inches; and the Cabo 40 convertible, at 77 inches. Don’t expect as much headroom in a smaller boat. However, there is a good deal of variance from builder to builder, so take notes when comparing.

Berths

Another issue with some smaller cruisers is that designers sometimes can’t resist trying to make their 26-foot express cruisers sleep as many people as their 32-footers. They can often fit the same number of berths in the boat, but — no surprise here, when you think about it — the beds are too short for an average adult.

Consider for a moment the dimensions of the beds likely to be in your home. A standard twin bed measures 75 inches long by 39 inches wide, while a queen (60 inches wide) and king (76 inches wide) both measure 80 inches long. Since 75 inches is the minimum length found at home, it is reasonable to expect the same standard on a boat of any size, including small cruisers, since it stands to reason that average-size (and tall) people are among those who buy and want to be able to sleep aboard smaller boats.

If you’re looking at a boat and the forward V-berth is 76 inches long and the dinette converts to a 68-inch berth, you might decide that’s fine, since the parents can sleep forward and two kids can sleep on the convertible dinette. But always measure all the berths before you buy a boat, since convertible dinettes — and sometimes forward berths, as well — can be a good deal shorter than 75 inches.

The longest berth on board express cruisers often is in the midcabin, situated below the bridge deck or helm area. In fact, 80-inch midcabin berths aren’t uncommon. If there’s enough headroom to sit up comfortably — around 36 inches — that might be the most desirable place to sleep. Also, be sure to measure the width of the berths, as they are rarely of standard size. Keep in mind that the 54-inch-wide double bed is the narrowest a couple can comfortably sleep on; a 60-inch-wide queen is much better for two. There’s no sense buying a boat to weekend on only to find out you can’t get a good night’s sleep. Back to the midcabin berth for a moment: Many of these so-called “cabins” have very limited headroom, often as low as 24 inches. It’s possible to sleep in such a small compartment, but it may seem very confining, especially for the person sleeping on the side away from the entrance. When you’re shopping for a boat be sure to lie down together, as if you were sleeping, to determine if it will work by virtue of the berth dimensions, as well as the headroom.

Also, there is a big difference in midcabins regarding accessibility from the main cabin. Some midcabins are pretty much wide open to the cabin, and those companionway stairs (with their steep rise and run) will have open risers, which makes the space seem less confining. Others are essentially walled off from the rest of the cabin, making them not only harder to get into and out of, but also somewhat inhospitable to the claustrophobic.

Berths also differ from beds at home in that they usually have foam mattresses, without the benefit of a box spring foundation. And the thickness and density of the foam mattresses can vary considerably from one boat to the next. If it’s thin foam, or if it’s not dense and supportive enough, it will never be comfortable. If you have to add an air mattress to make it comfortable, make sure there’s enough headroom left (especially in a midcabin) for you to fit comfortably. The key is to try it out, take measurements, and make an informed choice. If you like most everything else about the boat, you can always have a mattress made to fit.

Accessibility is the last point about berths. I’ve already discussed the issue of being able to comfortably get in and out of a midcabin berth; that’s mainly driven by the headroom inside the midcabin and by the clean, unobstructed width of the opening. Island berths forward are raised quite high, since the higher they are, the wider they can be. That’s because the beam inside the hull at the bow increases as the hull flares from the waterline up. The bow flares outward until it reaches its maximum beam at the sheer, or gunwale. So here’s another compromise confronting the boatbuilder: deciding how high they need to go to make the berth wide enough so the boat will sell.

On a smaller boat, especially one with a fine entry — which, by the way, helps give the boat a great ride in a head-sea — the forward berth will have to be quite high to be wide enough for two people to sleep on. Make sure you can get on and off it easily. Ideally it’s going to be accessible from both sides, so one person can get out of bed without disturbing the other.

A good ride vs. a cavernous cabin

Here’s a final caveat. While you might be attracted to the cruiser that has the biggest, widest and easiest-to-climb-into berth in the bow, be aware of the probable impact on the boat’s ride. If a forward berth is full, wide and low, then so are the hull’s chines, and that means the boat will ride hard, especially running into the seas. You just can’t have a full bow and a good ride.

Think of it this way: A good-riding hull has to have narrow sections forward that gradually taper out to the boat’s full beam. That allows the boat to meet each wave more gently, spreading out the impact over a few more milliseconds as the added buoyancy and dynamic lift created by the wave is spread out over a few additional milliseconds. You feel this more gradual impact, or dissipation of energy, as a much smoother, more comfortable ride. The boat with the full, blunt bow and low chines at the stem will ride hard, with the hull meeting the same wave with much more violence as buoyancy and dynamic lift increase much more rapidly. The blunt bow will really limit your ability to make headway when the wind starts to blow.

This brings us to the subject we opened with: that of compromise when it comes to powerboat design. The wider the companionway, the less room there is for a passenger seat to port, and so on. If you see a wide and low forward V-berth, it’s likely the boat will be a “crab-smasher” offshore, since the room for that berth was provided by a bow that’s too full too far forward. However, some boatbuilders do a much better job than others when it comes to the final product. A Four Winns 378, for example, has both a superb head-sea ride and a big island berth in the bow.

The bottom line with these accommodations issues is to be aware of what to look for, take your measuring tape along, take notes, and lie down a spell on those berths to make sure you’ll be able to sleep well.

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. Sorensen can be reached at eric@sorensensguide.com .