We struggle to find ways to reduce our footprint as we travel. Striving to save the planet is hard work when you're designing and building modern high performance yachts. But there are steps we can take in the right direction without building our boats out of biodegradable materials or figuring out how to turn our old boats into compost for orange orchards.
For a start we need to stop thinking about our boats simply in terms of length (and how much stuff we can carry in that length), and start thinking about how much air and water we are pushing around as we travel. Whatever it is we need to bring along; sleeping cabins, bathrooms, sundecks and water toys; spread it out lengthwise instead of stacking it in vertical layers. Thoughtful design is the solution.
There's a pretty basic formula that measures this ease of motion through the water. It's the displacement to length ratio (DLR). It compares hull length against the vessel's weight and it's a reliable measure of how much resistance we are working against in the water. It can be a reasonable indication of air resistance as well because if you're heavy and you're not that long its a fair indication that you have a lot of superstructure above the waterline. More weight drives the number up. Longer hulls bring it down. The lower the number the better.
A low DLR comes with a host of benefits. Lower fuel costs, extended range from a given fuel capacity, less sail area to drive the boat if it's a sailing boat. Longer hulls provide a more comfortable ride. And if your profile above the water is modest you have lower centre of gravity which means less roll and less pitch.
In the sensori range we've deployed two specific design features to enhance performance and promote a low DLR. The first is the reverse bow which promotes maximum hull length on the waterline for minimum cost, minimum weight and minimum windage. It's a no brainer solution for maximum efficiency. The second is the CS (canoe stern) hull shape which enhances performance by encouraging laminar flow over a significant portion of the under body. Both of these features are discussed in detail in separate articles you can find in The LAB.
Sensori 75 is a dive charter boat. She carries 12 guests in 6 double cabins with en-suites and has berths and bathrooms for up to 8 crew (5 is the normal compliment). The main navigation station is in the raised pilothouse and there is a second helm station on the flybridge but the flybridge is not enclosed. Sensori 75 carries a 5m tender on a lifting platform. She has a 3000nm range with Volvo Penta IPS drive engines
The top deck is a great space for lounging and yes, you can have a helm station up there but a roof over the top deck would not be in keeping with the concept at this size. There's accommodation space below decks for up to four double cabins with en-suites. If you're happy to sacrifice a bathroom or two you can have a large sundeck in the forward of the saloon with direct access through to the saloon.
Legs long enough to carry a flybridge with protective roof. Yes you can put a helm station up there but please don't close it in.
There's accommodation space for up to four double cabins with en-suites, and a couple of crew berths if you need them. Like the 52 there is space for a generous sundeck forward of the saloon with direct access through to the saloon.
The combined Newsletter for Grainger Designs and Rocket Factory Trimarans
Our DuFLEX kit systems streamline the construction process for amateurs and professional yards alike. More details here…