Engine Choices That Make Perfect Sense

When Aspen first created its patented proa hull, the asymmetrical design was driven by a single diesel engine to maximize efficiency and range. We perfected and proved this hull over many years and with many different diesel-powered Aspen models running thousands of miles. The development and popularity of modern gas outboards led us to adapt our proven hull form to provide the same benefits when powered by outboards.


inboard option

The Diesel Design Challenge

The benefits of a robust single diesel providing power for an efficient hull design are hard to beat but how do you place a single diesel in a two-hull design? If the engine is on one side wouldn’t it change the way the boat tracks? Each of the hulls in Aspen’s patented proa design are themselves asymmetrical (each hullform has a variance in shape between the starboard and port sides) so they slip through the water and play off each other to make the boat track straight in all speeds and conditions. The larger starboard hull provides plenty of engine room space for easy maintenance.

outboard option

Outboard Configurations No One Else Offers

With two hulls of different sizes, it makes sense to match the outboard power specifically to each hull. In this asymmetrical power setup, the two different outboards, one on each hull, are properly propped, and their RPMs synched to optimize performance as they work together. The engines also can be run one at a time in certain situations to improve the efficiency of single-engine operation for example when trolling.