Nordhavn did a nice project with the diesel-electric propulsion. For the owner of the boat, he like the security knowing that he could lose one, or both of his main engines, and still run off his generator, 3 prime movers to keep the electric motors turning (system would also run off the battery bank for about 4 hours, the owner said it was his favorite trick to pull up to the docks silent)
On larger sail boat, running both a main engine and a genarator, couldnt this type system be used, to give you a fail safe if one engine fails?
B Dock, (where the party is) Lake Mead Marina
Marillion 2 - 33.5 Hunter