I''m about to join a new boat fitted with a hydraulic drive system. I could do with someone telling me what it is all about since I will be living with it for the next year. Hopefully we will spend most of our lives sailing, not flogging the iron horse.
I cannot get an objective judgement (at this stage) from the owner who has elected to pay $10k''s instead of a normal direct drive deisel, and so he is physically and mentally committed.
As far as I understand it a 40hp diesel will drive a hyraulic pump and that will feed to two separate shafts. The contol system will allow inmdependent control of the two propellers, so you can have full ahead port and full astern stbd on the two shafts simultaneously.
What In am not clear about is (apart from the fact we can run a two shaft/prop system on a long keel which would otherwise require a single shaft to be mounted asymmetrically) what are the advantages and disadvantages of hydraulics versus direct drive via a gearbox? Is one, intrinsically, more reliable than the other? Don''t tell me hydraulic systems are more expensive ... I have see that!!!!!! ... are they any better than the traditional system most of us have managed to live alongside happily for many a year?