Saildrive vs Shaft Drive

[ranchero76]

Originally Posted by DotDun

I don't understand this phenomenon, but I'm sure there is a name for the desire to offer an opinion on a topic where one has zero experience/knowledge, maybe narcissism?

In the future, when you express your opinion, please disclose if your knowledge was gained via personal experience or from living your life thru others via the Internet.

You see, sometimes personal experience not strictly necessary. Humans can learn from others (sometimes). For example, you don't really need to feel and taste sh*t to tell it's sh*t. I can go and find these threads on CF, where real people described their experience with antifouling paint, for example. Besides, there's Delos experience, which anyone can go and check anytime. But you don't really need it, right? Besides, it's not topic of OP. And you're trying to shut me up from sharing their experience with others? Buddy, it's simply not very nice of you. If you had bad luck with bottom paint, or if you're in love with sail drives - it's fine. Just accept that there might be other people with other experiences - they really do exist out there, even if I'm not one of them.

[DotDun]

Originally Posted by ranchero76

You see, sometimes personal experience not strictly necessary. Humans can learn from others (sometimes). For example, you don't really need to feel and taste sh*t to tell it's sh*t. I can go and find these threads on CF, where real people described their experience with antifouling paint, for example. Besides, there's Delos experience, which anyone can go and check anytime. But you don't really need it, right? Besides, it's not topic of OP. And you're trying to shut me up from sharing their experience with others? Buddy, it's simply not very nice of you. If you had bad luck with bottom paint, or if you're in love with sail drives - it's fine. Just accept that there might be other people with other experiences - they really do exist out there, even if I'm not one of them.

You brought up the topic of my bottom paint refresh interval that took the thread off course.

You made the claim that saildrives are a bad choice using some frivolous reasoning without demonstrating a clue on how they work or how to maintain them.

You failed to attribute your opinions as being the experience of others. Why didn't you provide a link to the source of your wisdom?

[ranchero76]

Originally Posted by DotDun

You brought up the topic of my bottom paint refresh interval that took the thread off course.

You made the claim that saildrives are a bad choice using some frivolous reasoning without demonstrating a clue on how they work or how to maintain them.

You failed to attribute your opinions as being the experience of others. Why didn't you provide a link to the source of your wisdom?

Holy smokes! That's getting really funny.

You said you're servicing sail drives every time you paint bottom. Here's just one example -
http://www.cruisersforum.com/forums/...ml#post1925496

Paint lasted 7 years, hull cleaning - once per 6 months (!), which I wouldn't call "regular cleaning". That's regular paint, not coppercoat, which would last longer!
There are hundreds of other posts on this subject, anyone even with little brain able to find them.
I don't see other reason for haulout than bottom paint, prop service or emergency repairs.

So, will replacing seals on sail drive once per 7-10 years keep them good?
Because otherwise you will pay for haulout to do sail drive service, and haulout cost WILL BE part of sail drive service, which suddenly becomes very expensive.

I have general idea how the sail drive works. It is MECHANISM, while shaft drive is...well it's just shaft. So you're trying to convince me that expensive mechanism with gears and oil inside is more simple or reliable than shaft? I don't need personal experience for comparing things which even kid can compare! WTF!

[ranchero76]

Additionally - I've seen many posts "my sail drive broken", "my sail drive needs replacement","*** model of sail drive sucks and has serious design problems" and so on, but never seen even single post "my shaft drive sucks, I wish I'd have sail drive!"

[Souzag818]

Originally Posted by amarinesurveyor

Hi Everyone, this is my first post. I'm a surveyor and have looked at a lot of cats with sail dirves, and since the question was raised, I offer some things that I have found.
Sail drives have some advantages - they are less drag than a straight prop and strut, the prop thrust is horizontal and not on an angle as with a shaft drive, they take up less space, and they are less labor to install than a shaft drive.
The disadvantages are - they require more maintenance and are more prone to problems. Let me explain - 1. The gearcase (leg) is aluminum and is always submerged - you must be vigilant in keeping the zinc in good condition to protect the aluminum. The zincs can be replaced by a diver but ut is easier to do out of the water. 2. The shaft seals and gear oil should be replaced/changed at every haul-out. It is very common to find salt water in the gear oil due to leaking shaft seals - I think many people forget about the seals. Unfortuantely, to do both both jobs the boat needs to be out of the water. 3. The hole in the bottom of the boat is large compared to a shaft opening. Although you have 2 rubber seals if they both fail (very rare), you do have a large amount of water entering. 4. They are expensive to repair or replace.
There may be other advantages and disadvantages, but these stick out in my mind.
If I were buying a boat and had a choice, I would opt for a straight shaft drive, because they are easier to take care of, which means more time for enjoying the boating (what it's all about).

I had to chime in as I have a boat with a saildrive now, but previously had shaft drives, so I nave experience with both. I find the saildrive to be no more problems than the shaft drive. The zincs can be changed fairly easily by diving (I do this once a year regardless of condition). When I haul out, it's not a problem to drain the trans oil- just unscrew one screw and let it run. I've never found salt water in my oil. And as far as the big hole with rubber seals, it may have happened, but I've never known of anyone who sank after a failure of the rubber seals. In fact I changed mine out after 25 years(Volvo recommends every 7) and there were no cracks. It was still soft and pliable, and I took it and twisted, pinched, bent it every way I could. I think Volvo over builds the seal cause they know most people aren't going to replace it every 7 years. I find the saildrive to be much smoother than the shaft drive, and I don't have irritating drips and alignment issues. It's also not a problem to put in a dedicated thru hull for an intake, going to a raw water filter. About the only negative I've found is you need to haul out to remove the saildrive if it needs some work. Wasn't so high on them till I got one, but now...

[Sos]

Saildrives are also lighter which is a big plus in a catamaran and they give the designer more choice in engine location. Also approximately 10% more efficient due to horizontal alignment of the prop as opposed to a shaft that angles down.

[Pete7]

For a while, Volvo had a tank and a mock up using a sail drive for display at boat shows. The seal had a divers knife through it. That was fairly convincing when you saw it.

Surely the only reason to fit a sail drive is to keep the cost down by the manufacturer as its simpler to fit.

That said we chartered a Bavaria 32 with a SD and it handled beautifully, indeed parking in a crowded marina was childs play compared to say a long keeled yacht.

Pete

[DotDun]

Originally Posted by Pete7

For a while, Volvo had a tank and a mock up using a sail drive for display at boat shows. The seal had a divers knife through it. That was fairly convincing when you saw it.

Surely the only reason to fit a sail drive is to keep the cost down by the manufacturer as its simpler to fit.

That said we chartered a Bavaria 32 with a SD and it handled beautifully, indeed parking in a crowded marina was childs play compared to say a long keeled yacht.

Pete

That is one reason, but not the compelling reason. Saildrives allow better engine placement, especially in a catamaran. In cats, the engines are now in their ‘own space’ outside the living area, no lifting mattresses daily to check engine oil. This can’t be done with a shaft drive.

[DotDun]

Originally Posted by ranchero76

Holy smokes! That's getting really funny.

Not really, it’s actually sad! Do you or have you ever owned a boat? Most of your ramblings suggest that you haven’t!

Originally Posted by ranchero76

You said you're servicing sail drives every time you paint bottom. Here's just one example -
http://www.cruisersforum.com/forums/...ml#post1925496

Paint lasted 7 years, hull cleaning - once per 6 months (!), which I wouldn't call "regular cleaning". That's regular paint, not coppercoat, which would last longer!
There are hundreds of other posts on this subject, anyone even with little brain able to find them.
I don't see other reason for haulout than bottom paint, prop service or emergency repairs.

Ever changed a cutlass bearing? Aligned a shaft? Gotta haulout to do that.

Originally Posted by ranchero76

So, will replacing seals on sail drive once per 7-10 years keep them good?

Depends on the hours.

Originally Posted by ranchero76

Because otherwise you will pay for haulout to do sail drive service, and haulout cost WILL BE part of sail drive service, which suddenly becomes very expensive.

I have general idea how the sail drive works. It is MECHANISM, while shaft drive is...well it's just shaft. So you're trying to convince me that expensive mechanism with gears and oil inside is more simple or reliable than shaft? I don't need personal experience for comparing things which even kid can compare! WTF!

I’m not trying to convince you of anything, I don’t care what you think.

Show me where I stated a saildrive was more simple and more reliable than a shaft drive.

Stop with the baseless drivel, you may believe it makes you look smart, but it doesn’t.

[MartinR]

Originally Posted by ranchero76

Holy smokes! That's getting really funny.

You said you're servicing sail drives every time you paint bottom. Here's just one example -
http://www.cruisersforum.com/forums/...ml#post1925496

Paint lasted 7 years, hull cleaning - once per 6 months (!), which I wouldn't call "regular cleaning". That's regular paint, not coppercoat, which would last longer!
There are hundreds of other posts on this subject, anyone even with little brain able to find them.
I don't see other reason for haulout than bottom paint, prop service or emergency repairs.

So, will replacing seals on sail drive once per 7-10 years keep them good?
Because otherwise you will pay for haulout to do sail drive service, and haulout cost WILL BE part of sail drive service, which suddenly becomes very expensive.

I have general idea how the sail drive works. It is MECHANISM, while shaft drive is...well it's just shaft. So you're trying to convince me that expensive mechanism with gears and oil inside is more simple or reliable than shaft? I don't need personal experience for comparing things which even kid can compare! WTF!

Sorry, the mechanism is there on the shaft drive also. It is called a transmission.

Actually, there is little difference in maintenance between shaft drives and sail drives. For my part, I had to lift a boat to change an oil seal on a shaft drive (yes it had oil lubricated bearings). Oil seals on transmissions fail frequently (I had several, also bearings and ). An acquaintance of mine lost his boat when the shaft/prop assembly suddenly disappeared through the stern tube. Cutless bearings need to be changed on shaft drives as well. Anodes need to be replaced on shafts also. Nothing is maintenance free.

For my part, having had both (mostly shaft, though), I see no major drawbacks in sail-drives. Seals last for many years unless you are in abrasive water. Once you see water ingress, they are easily replaced. Or do it every 5 years or so as preventive maintenance, takes less than one hour. The drives are easy to work on If you have gouging of the shaft from the seals, there is no reason for replacement, you repair this permanently with a bearing sleeve, just as you do on oil-sealed shafts.

[robert sailor]

Saildrives have been around forever. In the past in some boats you had a choice between shaft drive and sail drive...sail drives were a lot cheaper. Resale also reflected the lower price for those boats with sail drives. In those days even though more expensive most buyers paid the extra for shaft drives. Today's high production boat builders throw nickels around like manhole covers so because sail drives are much cheaper to buy and take much less time to install that is pretty much all that is available. If today's buyers had a choice to pay more for a shaft drive then we could debate it but that choice is not available so it's really a moot point.

[boom23]

I, and several cruisers I've met, have had bad experiences with Yanmar saildrives. I've seen mostly slippage problems. A quick internet search will bring up problem posts.
I do not have experience with Volvo saildrives.

For serious cruising, you want as problem-free equipment as possible. I may be wrong but, I believe many of the serious cruising boats do not use saildrives.

My next boat has a time proven standard transmission and shaft.

To each his own...

[rom]

Originally Posted by boom23

I, and several cruisers I've met, have had bad experiences with Yanmar saildrives. I've seen mostly slippage problems. A quick internet search will bring up problem posts.
I do not have experience with Volvo saildrives.

For serious cruising, you want as problem-free equipment as possible. I may be wrong but, I believe many of the serious cruising boats do not use saildrives.

My next boat has a time proven standard transmission and shaft.

To each his own...

I have seen SD slippage problems around me as well. But mostly I have seen trouble free SD. No problem on mine yet (and I have two SD50 yanmar).

As for "serious cruising boats", Catana, Outremer, Marsaudon TS, Tournier Freydis, all use saildrives on their boat. But maybe you should define serious.

Also, someone said here even bigger cats use SD. This is not true. Above a certain weight & power they all use shaft. Lagoon 560 and above for example. I believe SDs are limited to ~80hp, but could be wrong on this.

[smj]

Having owned both if I had my choice I would pick shaft drive no doubt. But if the boat I really wanted only came in saildrive it wouldn’t stop me from purchasing it.

[Captain Bill]

This saildrive versus shaft drive seems to be a religious issue and no one will convince those with an opposite opinion. I had some issues with my saildrives last summer and was doing a bunch of research. What I found is that no sailboat transmission, either saildrive of shaft is designed for cruisers. Cruisers are simply not a big enough part of their market. Sailboat transmissions are designed to get you in and out of the slip and down the channel to open water where they expect you to sail. Their target market is weekend sailors. They are not designed to motor hundreds of miles in calm winds. From what I could gather most have a target design life of 1500 hours. They expect this to take 15-30 years to accumulate. This applies to saildrives and shaft drive transmissions.

I would note that I have personally sheared a shaft coupling and pulled the shaft out after hitting a crab pot, which resulted in a lot of water in the boat. I have hit several crab and lobster lines with my saildrives and never had a problem with water in the boat.