Because it's so far from being practically useful.I thought the concept of sail and solar was very interesting and the unique sails being used got my attention. But it seems a lot of vision in this and other projects and then things keep dying away.
Since many boats spend 75% of their time in a marina, I would think that a hybrid drive system would be able to keep the weekend boater satisfied. It won't supply all his locomotion needs, but the diesel will be run considerably less.
There is a new Greenline 33 that just showed up in our marina. Very interesting boat. It's totally silent when it leaves and returns. I haven't been able to talk to the owners very much about it. The website shows it comes with a Volvo D3 and an electric motor.
So far, I don't see how it helps. Greenline is the largest seller of Hybrids so focusing on a Greenline 39, on a fully charged battery pack it can run 20 miles at 4 knots. At 6.5 knots it can go about half that. So, what is it really doing for you?
Time to consider building diesel electric trawlers?
Well, there's another thread on Wider 150, which takes a very unique approach to diesel electric.
BrandB, maybe I should have said small trawlers, less than 50ft. OAL.
Generally speaking, cruise ships are diesel electric.
I know what you mean, but also these things start larger. You see it accepted in 150' boats and it may well make it to 50'.
I ponder building a steam engine driven boat using old tires to fire the boiler. You can find old tires anywhere.
FYI Foss Marine operates hybrid tugs.
Foss’s second hybrid tugboat employs new, more-powerful lithium polymer batteries - Professional Mariner - September 2012
I was being a little facetious about the steam plant & tires. I was a steam plant engineer, so fully aware of the downsides and complexities. But my evil side still wants to do it!!!
I ponder building a steam engine driven boat using old tires to fire the boiler. You can find old tires anywhere.