Outboard Power Like No Other Boat
At Aspen we understand that many boaters today are looking for outboard power, and we’ve received a lot of input from our owners and prospective buyers. Over the years buyers have said they like what we do in terms of efficiency, stability, cabin space, and style, but wanted the versatility outboards provide. Some needed to cut across sandbars and draft was an issue. Others travel to areas where it is easier to service outboards, or head far offshore and prefer the redundancy and peace of mind twin engines provide. Some buyers just prefer outboards: Having grown up with them, they understand them better.
Aspen’s Founder and President Larry Graf noticed his earlier-designed twin-outboard catamarans could successfully run off a single engine with slight steering corrections. And he has always understood the efficiency, speed, and performance outboards can achieve. With the technological developments that outboards have undergone in the last decade, they are cleaner, quieter, and more fuel efficient than ever. Larry set out to integrate outboard power into his patented proa design to provide added benefits and efficiency.
Larry saw an opportunity to incorporate outboard power to create even more of an advantage for Aspen owners. He tested our asymmetrical hulls with a single engine like on our inboard boats and they ran well. Since many outboard fishermen would also want to troll, he then experimented with adding a smaller trolling motor to the other hull. At first he thought that the trolling motor would be tilted up when running at speed but he soon found that the smaller outboard added appendage drag that helped with tracking, largely because the outboard-powered hulls lacked the keel of the inboard boats. He soon realized that if you are going to have both engines in the water you might as well power them both while running. Dialing in the size and power of the engines as well as the hull shape he came up with the optimal running setup and the first asymmetrical outboard-powered catamaran was born.
As with any new model or change, we do extensive testing and sea-trialing. The results of this power package were surprisingly good. The outboard model topped out at speeds that were 20 percent faster than the diesel inboard version of the same boat. We categorize the acceleration as startling, and we’ll leave it at that. These outboards are a lot different than those that many of us used to know: They’re actually quieter at cruising speed than the inboard diesel. With power tilt, we can reduce the draft of the boat to 22 inches. On one engine she’ll run at 8 knots, and single-engine operation also can reduce trolling speed to less than 1.8 knots.
While our outboard-powered boats have some advantages over the diesel-powered boats, there are some differences to consider. For example, a boat powered by the two outboards will burn 15 percent more fuel than the single-diesel model. Outboards will not last as long as a robust diesel engine, but repowering is easier. Storing a dinghy is a little trickier with outboards, but we have designed a patent-pending davit system that is fast and easy to use.
Outboard power is very popular today and many owners are willing to sacrifice some fuel efficiency and engine longevity for faster top-end speeds and other advantages. Aspen delivers top efficiency in their outboard models compared to other outboard-driven boats in their size and class and continues to offer a full line of diesel inboards too.