Larry Graf, founder and chief designer of Aspen Power Catamarans, has taken his boats to some of the planet’s most remote and demanding environments — from Siberia to Canada’s Northwest Territories and Alaska. Those years of hands-on cruising and engineering have culminated in the 37-foot Aspen C108, a design that prioritizes long-range efficiency, seaworthiness and practical liveaboard comfort for serious adventurers.
At the heart of the C108’s performance is Aspen’s asymmetrical hull concept. The port hull is 35 percent slimmer than the starboard hull, a deliberate choice that dramatically reduces resistance. According to Graf, the finer hull form cuts the effort required to push the boat through water by roughly 60 percent versus a conventionally matched pair of hulls. The C108’s very fine entry angles and careful load distribution ensure both hulls behave similarly in the water, delivering a steady, predictable ride.
Graf has proven the concept on extended expeditions — notably a 1,200-mile journey down the Mackenzie River and into the Arctic on a 32-foot Aspen C100. On that trip he faced strong opposing currents and long distances between fuel stops, lessons that shaped the C108’s requirements: superior fuel economy, dependable range and rugged construction for remote travel.
Power and range for the C108 are tailored to that mission profile. With a 115-hp Yamaha on the port hull and a 200-hp Yamaha on the starboard hull, the C108 reportedly consumes about 8.5–9 gph at a comfortable 17 knots and about 22 gph wide-open at 27 knots. Standard fuel capacity is 130 gallons, with an optional 180-gallon tank for owners who need extended range; that larger tank is expected to provide more than 300 miles at cruising speed, making serious coastal and inland passages feasible without frequent refueling.
Built for rugged use, the C108’s hull and structure emphasize durability. The hull is fiberglass with a Kevlar-reinforced leading edge and a double-bottom design that omits wood entirely. Graf says the structural materials are lighter and more durable than traditional plywood, engineered to withstand impacts with logs and other hazards without leaking. This construction approach is aimed at owners who want a trustworthy, low-maintenance platform for exploring remote coastlines and rivers.
Interior design for the C108 was driven largely by customer feedback. Although it’s only one foot longer than the earlier C107, the C108 adds 8 inches of beam and several important layout improvements prompted directly by owner requests. The new model began from a simple but specific desire: a larger dinette and a modest aft shift of the bulkhead. That request, echoed by other prospective buyers during the 2018 Seattle Boat Show, led Graf to produce full-scale mockups and quickly iterate the layout based on hands-on feedback.
The result is a more spacious, user-friendly interior. The reshaped cockpit is both wider and two feet longer thanks to the aft bulkhead adjustment, and the reconfigured galley and stateroom access create a convenient footwell under the galley for comfortable standing room. The C108 adds a third stateroom located abaft the head on the starboard side, while the forward master stateroom features an 84-by-84-inch berth. The dinette now seats six, up from four in the C107, making the boat significantly more sociable for cruising families or groups.
Practicality remains a central theme: the C108 is trailerable — essentially as large as a comfortable, trailerable cruiser can be — and offers options such as a diesel heater and air conditioning for year-round cruising from cold northern waters to tropical climates. These systems, combined with the boat’s quiet and fuel-efficient powertrain, aim to provide a comfortable, low-impact cruising experience.
Graf describes the Aspen C108 as a boat for adventurers who want serious capability without excessive complexity. Its combination of asymmetrical hull efficiency, rugged fiberglass and Kevlar construction, thoughtful owner-driven interiors and trailerability make it a versatile choice for long-range coastal and inland cruising. For sailors and powerboaters seeking a clean, economical cruising platform that balances range, comfort and seaworthiness, the C108 represents a practical evolution of Aspen’s compact expedition catamaran philosophy.
Specifications:
LOA: 37’6”
Beam: 10’8”
Draft: 22”
Displ: 10,840 lbs.
Power: 200-hp (starboard) & 115-hp (port) Yamahas
This article was originally published in the March 2021 issue.