Pros and Cons of Sail Drive

[jokler]

What has been your experience with Sail Drives? I've been told that if I'm going to buy a boat for long haul cruising then there not for me because they're to hard to work on or get repaired. I look forward to your opinions.

[Vasco]

The advantage of a saildrive is that it's cheaper to install when the boat is built.

[jokler]

Do you have a saildrive? I'm not so worried about the upfront cost as much as having to repair equipment, or finding someone to repair them. Any thoughts?

[Tellie]

Having part of your transmission constantly in the water does come with it's issues. I don't know that there are alot of overwhelming issues that make sail drive undesirable for long distance sailing. Mine are 14 years old and have been a lot of places and they are still going strong. Changing the oil is a pain and means the boat has to be hauled. But I find hauling every year or two to do other maintenace is required and I tackle the oil and a new set of seals then. Changing the zincs underwater is a bit fun especially if you have folding props. But it can be done you just have to be careful you don't drop the bolts. I tie a 5 gallon bucket under the prop to help catch anything that might drop and the buckets a good place to keep tools and parts while changing out the zincs. Changing out the boots can be a bit expensive. But I've found they last a whole lot longer than the recommened time the manufacturer recommends their replacement to be. On a Cat they are two more long legs to catch lobster traps. That's always a pain. But over all mine have been very reliable and they keep the props deep in the water as opposed to outbaords attached to Cats.

[First Mate]

Originally Posted by Vasco

The advantage of a saildrive is that it's cheaper to install when the boat is built.

the sail drive allows more accommodations from the added interior space inside the hulls for the floating condo - which is appealing to live aboards.

or so I've been told.

what does the sail drive add to interior hull accommodations - 12" or more? 8" - that's a lot on a boat.

I think a perfect boat would just be longer in length and not have sail drives - but, in case you haven't heard this already, every boat is a compromise (geez I hate that saying)

[Talbot]

Saildrive primary advantage is to the boat builder - it is a lot easier to install. You dont have a shaft and a P bracket and alignment to worry about.

For the owner, it not only shortens the installation from the stern, but also provides additional space at the stern for other things (dont need access to a shaft seal. Thus the biggest advantage is space. It means that you can create a small area that can be protected with watertight bulkheads, and thus significantly increase the safety of the vessel.

It also means that the propellor is in line with the shape of the laminar flow, and thus able to be more efficient than a shaft pushing downwards as well as back. It allows the propellor to be a lot further away from the hull, so it is not so affected by any turbulence from interaction with the hull.


Its biggest weakness is that this is an aluminium leg permanently in salt water, it is more prone to damage than a shaft drive, the seawater on some systems is actually sucked through the leg, and this tends to be a much smalller opening than a normal seacock, and vulnerable to clogging by little crustaceans.

[Dave852]

Sail drives are quieter

[Southern Star]

Sail drives do have some advantages:

1. they are typically quieter, as has already been pointed out.
2. they do not (should not) permit water into the bilge, nor do they require a stuffing box and maintenance of the same in what is typically a very difficult to access location.
3. they take up less space and, in a catamaran, permit aft cabins and engine/transmission access from the exterior and/or props in front of the rudders, where they are most effective.

Brad

[FSMike]

I've not had much experience with saildrives, but I wonder about failure of the gaskets/boots/seals whatever you call them. I've never seen a stuffing box leak that I couldn't stop or at least slow down to a dull roar, but I'm not sure how easy that would be with a sail drive. Anybody out there had that experience?

[Southern Star]

I've never had a failure Mike, and further there is an alarm that goes off if the inner boot starts to leak (although I haven't experienced that either). Frankly, i cannot imagine what could lead to a catastrophic failure of the inner boot short of a collision that tore the saildrive out of the bottom of the boat. At that point you are apt to have a ton of big holes to worry about!

brad

[Tropic Cat]

Originally Posted by First Mate

the sail drive allows more accommodations from the added interior space inside the hulls for the floating condo - which is appealing to live aboards.

or so I've been told.

what does the sail drive add to interior hull accommodations - 12" or more? 8" - that's a lot on a boat.

I think it's a bit more. On my boat the difference would be closer to 1 1/2 - 2 feet.

I have shafts and P bracket. I prefer them over sail drives. My engines are mid boat mounted for proper boat balance. The engine/transmission access is from the exterior and my props are in front of the rudders, where they are most effective.

[Tropic Cat]

Originally Posted by Southern Star

I've never had a failure Mike, and further there is an alarm that goes off if the inner boot starts to leak (although I haven't experienced that either). Frankly, i cannot imagine what could lead to a catastrophic failure of the inner boot short of a collision that tore the saildrive out of the bottom of the boat. At that point you are apt to have a ton of big holes to worry about!

I watched a video of a rescue at sea where a Cat with sail drives was sailing along, minding it's own business when a whale surfaced directly under the boat. One of the sail drives was square on the whale's back and was driven straight up and through the boat. Needless to say, this was catastrophic and mayday and rescue followed.

Probably 1 in a million, but it happened and there's video on the net of the rescue.

[blgklr]

If I liked the boat a saildrive would not stop me from buying aslong as the make of saildrive was one I liked.

[Reality Check]

Had a sail drive on a mono Chrysler 26. The boot gasket was about more than a foot to 18 inches and the bolt down to the lip was the main point of concern for failure. It is obviously below the surface and any barnacle growth that was not meticulously taken care of could ware through the boot and cause a puncher. I've seen one that had marine growth all around the seal and significant ware on the boot. Appeared to me a good pounding in a northern swell where the aft slams down would be sufficient to cause major problems with out any form of collision.

I loved the little boat but would never take her on a light blue water cruise.

[craig boorman]

Just fixed the seals on my sail drives, one was leaking in seawater for 8 months, only used that engine for docking and changed gear oil about once a month. I was worried about it but haul out wasn't sceduled till last week. I have sd50 yanmar drives and had yanmar mech. do the work, once all was opened we were impressed on how simple and strong those gears were, the mech. said still looks new and no ware. I will do this work myself next time and I may do this work underwater if needed. It can be done.