Hatteras GT59 | Grady-White Freedom 255 | Galeon 640 Fly - 08/22/21

While convertibles like the Hatteras GT59 above are designed for fishing and not entertaining, the fact is they are good at that, too – with a little imagination. In our experience, the cockpit makes a perfect place for a cocktail party on an evening cruise. Put a table in the middle with beverages, ice and finger food and you’re all set. (That’s what they do in Europe.) Generally, men like to lean or sit on the covering boards and the ladies will sit on the mezzanine. Hatteras is flexible when it comes to the layout of the salon/galley and accommodations. Again, use your imagination. Get rid of the galley’s aft counter and open up the space. Below, Hatteras has several different layout plans but for the money this boat will cost, you can come up with your own. For example, try three en suite staterooms. Make the forward cabin for grandchildren with bunks to port and starboard. Think out of the box. More...  

Grady-White’s Freedom 255 can be powered by up to a single 300-hp outboard or by twin 150s. We haven’t tested this boat so, unfortunately, we can’t say what her single vs. twin metrics are. Happily, the techs at Grady have tested the boat both ways and this is what they report: Top Speed – 48.1 mph for the twins; 43.5 mph for the single. Best cruise – 27.3 mph/2.42 mpg for the twins at 3700 rpm; 25.1 mph/2.37 mpg at 4000 rpm for the single. (BoatTEST considers “best cruise” as planing speed that provides the greatest mpg.)

The twins also get the boat up on plane at a lower rpm – the twins were on plane at 3000 going 18.8 mph, while the single 300 was still chugging along at 10.5 mph at 3000 rpm. The boat with the twins weighed 214 lbs. (97.07 kg) more than the 255 with the single plus she had a fiberglass hardtop creating added windage, unlike the single-engine 255. Both factors should have made the going harder for the twins, but they were clearly able to overcome the handicaps of added weight and windage. 

Why is there such a difference when both boats had 300 hp in total? Two important reasons: 1) the 150 Yamahas are 2.7 L displacement each, which totals 5.4 L for both, compared to 4.2 L displacement for the single 300. (No replacement for displacement?) 2) The twins were swinging two 14 1/4" x 18" props, compared to the 300’s single 15 3/4" x 15" props, so the twins simply had much more blade surface in the water than the single. It is blade surface that turns engine horsepower into thrust. Even though the 300 had a larger diameter prop, it couldn’t come close to matching the blade surface area of two slightly smaller props. This also means that the Freedom 255 powered by twins has much more weight-carrying capacity for a given speed than the single engine-powered boat. The final piece of the puzzle is the cost of the engines. Two loose 150s will cost about $4,500 more than a single loose 300. More...