Just as construction technology has produced weight savings, so have advances in propulsion, components and system placement. Pod-drives are lighter than inboards or stern-drives and, because they’re more efficient, engines can be smaller. Some designers are even looking at using lightweight turbine engines in series.
Marshall estimates that using carbon-fiber propellers produces an 80 percent weight savings per wheel over traditional metal props. Plus, carbon-fiber propellers are easier to repair because the blades can be taken off individually.
Zurn explained that companies that make galley appliances, air-conditioning systems and generators are all competing to make smaller, lighter units, which reduces the overall weight of the boat. Even LED televisions contribute to weight savings.
Rigging also helps lighten the load. For example, positioning the generator as close to the water intakes as possible reduces the amount of plumbing needed.
Zurn said that owners who take an extra-long look at how they will use the boat could help reduce the weight before construction even starts. Owners who are mainly going to use the boat for entertaining, as opposed to extended cruising, can go with one or two staterooms and save the weight of the third.
With all the positives of going light, there are negatives — mainly cost. Building a lightweight vessel out of exotic materials is complicated. “You can take a 25-foot boat and build it in a production shop in a day or two,” Peters said. “Build the boat in advanced composites, and you’re going to be at it for a month.” Fabricating cored interior panels takes more steps and requires additional manpower. Building a light interior can also be more costly than constructing a lightweight hull and deck.
Marshall said that, in some cases, changing people’s perceptions of lightweight boats can be a challenge. “When we build a lightweight boat, we build lightweight cabinets, but we keep the doors heavy,” he said. This gives the owner the perception that the boat is built for heavy-duty use — they feel more substantial.
In terms of performance, if you build the boat too light, it won’t ride well in rough conditions. Lindsay said understanding the design is critical. He explained that Zurn understood this from the beginning when developing the MJM line. These boats have a different bottom design from that of a traditional Down East hull, because they were intended to be light from the start.
Building a boat with exotic materials also means that people who repair them need to know their business. Marshall explained that it’s more difficult to make a repair to a door cored with honeycomb aluminum than to a solid-wood door. Lindsay said that there are enough skilled technicians worldwide that it’s not an issue. “We have boats all over the world,” he said. “There’s a network of people who know each other.”
In the growing world of lightweight yachts, the pros far outweigh the cons. Efficiency, fuel economy and the wow factor of performance mean that weight loss is here to stay.
