From Russell Hunt, past president of Buzzard Bay Cats
By what measure is a boat considered fuel efficient? Is 0.5 MPG efficient? Well, it is if that boat’s a 70 foot sportfish traveling at 25 knots. Is 5 mpg efficient? It is not if it’s an 18 foot light tackle boat. Fuel efficiency is of course a relative statement. We must first look at the intended use. Do I want to cruise offshore in potentially rough conditions, or will I cruise the coast via the ICW, always staying in protected waters? To be able to handle rough water comfortably may require a heavier boat with a deeper v-hull to maintain comfort in a seaway, at the expense of fuel efficiency. Do you prefer to cruise at slow speeds, or do you want to run fast? Perhaps you would like the ability to cruise at a relaxed pace efficiently, and at times, run fast in order to outrun bad weather or just for time constraints. In the traditional mono-hull world, all of these choices demand that serious compromises be made. No boat will not do it all…with a few exceptions. It has been our position at Buzzards Bay Catamarans that a well designed, carefully built catamaran, utilizing advanced composite construction for lightweight, and a high-speed displacement hull shape for low drag, can in fact do it all with very little compromise. Our Buzzards Bay 34 delivers best in class interior, significantly higher levels of ride comfort, fast cruise speeds, and outstanding fuel efficiency. If you’ve been following these blogs, you understand our advantages when it comes to sea-keeping ability, interior space, and have a good understanding of our speed performance. For the Buzzards Bay Blog No 5, we would like to evaluate our fuel efficiency advantages against competitive boats over a wide speed spectrum.
To accomplish this, we’ve assembled a broad mix of similar mission / size boats and we’ve broken them down into two groups, outboards and diesels. To make the results as meaningful as possible, we gathered single engine, twin engine, and pod drive competitors, so as to leave no questions unanswered.
We’ve included some larger (by length) vessels, the MJM 40z, Grady White 36, Pursuit 375, and Back Cove 37 because these vessel match up to our Buzzards Bay 34 in actual size and space on board. However, to be fair, we did include their smaller brothers (Grady White 33, Pursuit 345, MJM 34z) so there were no boats we were trying to “duck” in this comparison.
For a little fun (and more than a little perspective) we also included a vessel that represents an extreme attempt at achieving fuel efficiency; the Greenline 33 Hybrid, which is a fully enclosed pilot house cruiser featuring a layout similar to the Buzzards Bay 34. It is powered by an inboard diesel engine that is fitted with an integral generator / motor. The operator has the ability to operate on battery power alone, diesel and battery, or just diesel, all with integral solar charging. Its system is too complex to adequately describe here, but in nut shell, it is an attempt to bring automotive style plug in hybrid technology to boats. Will the same fuel efficiency advantages that hybrid cars enjoy carry over to express cruisers? We’ll see.
The above chart is the relative fuel cost per gallon of each vessel, adjusted for their average fuel efficiency at the measured speeds (15, 20, 25, and 30 MPH). We set the Buzzards Bay 34 operating cost at current prices ($3.50 per gallon of diesel, we can dream, right?).
The MJM 34 is about 13% more expensive to operate than the Buzzards Bay 34, with its owner paying a relative fuel cost penalty of $0.44 per gallon over the Buzzards Bay 34, followed by the MJM 40z ( $5.22 per gallon), Back Cove 37 ($5.85 per gallon), Sabre 34 ($6.55 per gallon), and lastly, the Tiara 34 at a pricey $7.71 per gallon, a 120% operating cost increase over the Buzzards Bay 34.
The MJM 40 has the most range at 554 miles, with the Buzzards Bay in second at 513 miles (on roughly half the fuel), followed by the Back Cove 37 with 454 miles, Sabre 34 (356 miles), MJM 34 (320 miles) and lastly the Tiara with 281 miles.
Among purpose built vessels aimed squarely at fuel efficiency, pod powered, single and twin engine installations, the Buzzards Bay 34 is at or near the head of the class in every comparison. With an optional fuel capacity increase of 30 gallons, there isn’t a category she would come second in.
How does the diesel powered Buzzards Bay 34 compare to the most extreme vessel here, the Greenline 33 Hyrbid? At 15 mph, the Buzzards Bay is 40% more fuel efficient than
the Hybrid. Unfortunately, the Hybrid is not able to achieve speeds to 20 mph, according to the test. This performance may seem a little disappointing. Still, it has the ability to operate very quietly on electric power alone, and for some, the onboard serenity that low noise levels produce is alluring enough on its own merit. To these folks I say consider an outboard powered Buzzards Bay. At 15 mph, the efficiency nearly matches that of the Hyrbid (2.05 vs 2.11) and at any speed above 7 mph, our Mercury Verado outboard powered Buzzards Bay is actually quieter because the Hybrid has to run its diesel. In full electric mode the Hybrid is limited to a range of 20 miles at 6 mph. I think there’s allot of compromise here for very little performance. It’s neat and different, but are there real benefits to the owner?
There you have it. Whether diesel or outboard powered the Buzzards Bay 34’s fuel efficiency is outstanding. Factoring in her class leading size, ride comfort, and stability, and her dominating performance is even more impressive. This is what a good catamaran can deliver. No gimmicks, no unproven technology, no compromises. Just good catamaran design work (courtesy Chris White Designs) and light weight advanced composite construction techniques with quality craftsmanship.