Taking on Ballast
Our test boat was a late 1990s 24' Sea Ray Sundeck powered by a 220-hp 5.7L MerCruiser. It has a common hull you see on plenty of boats and reasonable power. It's also a deckboat, which is a perfect test bed. Few boats get more people and gear piled into them than a deck. Ours had a capacity sticker rating for 12 passengers or 2,000 pounds.
To start we established baseline numbers at 800 pounds, the total weight of our test team and assorted gear. It's a common load for this boat. Based on the national average, a four-man crew would be close to this. Then we added weight in 400-pound increments until we reached the boat's 2,000-pound capacity. To do this we used Fly High water ballast bags, which are primarily used to boost wake size when wakeboarding. The bags were placed throughout the boat to mimic a safe passenger load.
For most of the experiment, we relied on our usual boat-testing tools. Fuel flow as well as running and banking angles were all noted. Speed and acceleration curves were obtained using the Stalker Acceleration System, the industry standard in radar-based testing. Finally, differences in stopping and turning distances were measured with GPS.
Then there was the more subjective part of the test, the seat-of-the-pants perspective from our crew and the boat's owner. From this, we noted any subtle handling abnormalities or safety concerns.
That's how we did it. Now here's what we learned.