Larry Graf, founder and chief designer at Aspen Power Catamarans, has adventured by sea to such remote waypoints as Siberia, Canada’s Northwest Territories and Alaska. So, he knows as well as anyone what makes a good cruising boat. His years of experience behind the helm and behind the computer engineering models has now manifested into the 37-foot Aspen C108.
Chief on the list of requirements for cruising boats is efficiency, which is why Aspen catamarans run on asymmetrical hulls. The port hull is 35 percent thinner than the starboard hull, and Graf says the narrower beam reduces by 60 percent the effort it takes to push the boat through the water.
“A finer hull is dramatically more efficient,” Graf says, “but we still need the one larger hull for the accommodations and machinery that need to be there.”
The two hulls have the same load per square foot, so they feel exactly the same in the water, he says. Their very fine half-hull entry angles are designed to further improve efficiency.
Graf has put this hull design to the test on ambitious expeditions, including a 1,200-mile trip down the Mackenzie River, through the wilderness and into the Arctic Ocean on a 32-foot Aspen C100. He battled a 4- to 6-knot current the entire way back up the river, with 250 miles between fuel stops. To do a trip like that, Graf says, “a boat has to be incredibly fuel-efficient at range.”
In keeping with that requirement, the C108 reportedly burns 8.5 to 9 gph at 17 knots, and 22 gph at 27 knots at wide-open throttle, with a 115-hp Yamaha on the port hull and a 200-hp engine to starboard. While 130 gallons of fuel is standard, owners can opt for 180 gallons, which should allow more than 300 miles of range at cruising speed.
Venturing off into the wild also requires a reliable and seaworthy hull. Construction on the C108 is fiberglass, with a leading edge that is Kevlar-reinforced. There is no wood anywhere in the hull, and the double-bottom hull is designed to be strong enough to run over logs and other obstacles without breaking or letting in any water. “The structures are half the weight of plywood and should last more than 100 years,” Graf says.
Feedback from Aspen customers helped drive the C108’s interior design. While only 1 foot longer than the C107, this new model has 8 additional inches of beam and numerous new features. In fact, the entire C108 concept stemmed from one couple’s request.
“It started with a woman from Seattle and her husband. He loved the C107 and wanted that, but she didn’t like the table,” Graf says. “He called and said, ‘Larry, we have a problem. She doesn’t want the boat unless she can have the dinette from the 40, and she wants the aft bulkhead moved back a little.’”
A few hours later, Graf received a call from a woman in Canada who also wanted a larger dinette. This was during the 2018 Seattle Boat Show, and Graf got to work on new sketches that night. He showed them to current and potential owners the following day. “They all loved the sketches to the point where they were willing to put money on it,” Graf says.
Graf then built a full-scale, computer-cut mock-up of the new model and invited those customers to walk through it with him. “Listening to what they liked and didn’t like, we adjusted the galley, stateroom and how you access the boat a little bit,” he says. “We ended up with a boat that they love and future customers are also really interested in buying.”
One change is added capacity throughout. The reshaped cockpit, in addition to being 8 inches wider, is also 2 feet longer thanks to the bulkhead being moved farther aft. By moving the bulkhead, Graf was also able to create a footwell in the stateroom under the galley, so owners have a place to stand. The C108 adds a third stateroom, abaft the head compartment on the starboard side. The master stateroom forward has an 84-by-84-inch berth, and the dinette now seats six people compared to the C107’s four.
And, the boat is trailerable: “The 108 is essentially as big as you can go and still trailer it,” Graf says. It also can be equipped with a diesel heater, air conditioning or both, allowing buyers to explore from the Arctic to the Caribbean and beyond. “The boat is intended for the guy who’s doing adventure trips,” Graf says. “This is a big cruiser that’s nice to the environment, super quiet when cruising, and easy on your wallet.”
Displ: 10,840 lbs.
Power: 200-hp (starboard) & 115-hp (port) Yamahas
This article was originally published in the March 2021 issue.