Opinions on Saildrive v Shaft

[aquaholic]

Looking to buy my fist yacht and have found a boat which ticks all the boxes except it is fitted with a saildrive as opposed to a straight shaft, my worry is after spending many years on motor boats I have come to know how expensive sterndrive units and outboard legs can be, iam concerned that saildrives could suffer the same problems. If anyone could advise what the cost would be to replace that would also be usefull to know.

 

[Tranona]

Don't worry about it. The new boat market is now about 50/50 and Saildrives have been around for over 20 years and there are thousands in use - Bavaria make over 3000 saildrive boats a year!. Many builders fit both on different models in their range as appropriate to their target market. The advantage is that they are generally smoother and quieter and do not have prop walk in the same way that a shaft does. Perhaps need a little more care in annual servicing making sure the anode on the leg is replaced and gearbox/leg oil changed.

Volvo suggest the sealing diaphragm is replaced every 7 years, but many don't and you hear from people who do replace that there is nothing wrong with the old one.

There is no comparison with the "problems" of sterndrives as there is no vulnerable steering and lift mechanism, nor do they operate in the air/water interface.

Make your choice on the merits of the boat, whilst of course having the usual survey.

 

[aquaholic]

many thanks, I guess that was what I wanted to hear as everything else on the boat seems to work for us /forums/images/graemlins/smile.gif

 

[gianenrico]

17 years of problemless use of a VP saildrive coupled to an 18 HP VP 2002.
For sake of commercial integrity I changed the rubber seal before selling the boat: was good as new.

One suggestion: prior to launch do installa a wire cutter, a stripper or any other contraption to reduce the rissk of tangling up.
MIND You: in 3 years with the new shaft propelled boat I had a 300% increase in tangling (1 vs. 3!).
Cheers

 

[Dipper]

I agree with the other two replies. My Volvo saildrive is now 21 years old and has had no problems.

The propeller is deeper in the water which I would guess gives better grip especially if the boat is pitching. Also, if you have a fin keel the propeller is tucked nicely behind the keel for a little bit of extra protection against ropes. One characteristic of the handling is that you don't get much prop wash onto the rudder. This can be both a disadvantage (if you want to use it) or an advantage (if it would push you the wrong way).

Some people worry about the large hole in the hull but I have never heard of the seals failing. On the other hand, a couple of my friends with shaft driven boats have had the shaft seals fail or the shaft fall out and have only just managed to save the boat from sinking. Those round the world racing yachts have saildrives so they can't be too prone to failure!

I have seen pictures of casings that have rotted away alarmingly quickly. It is very important to ensure you have an effective anode fitted and that you do NOT use a copper based antifoul on the saildrive itself. I use an antifoul for aluminium hulls on the saildrive leg and an area of the hull in the vicinity of the leg. In answer to your main question, they are expensive to replace but I don't have a figure to hand.