Buying a boat with a saildrive - got a few questions

[LToast]

Hi all. In the UK here, currently liveaboard on a steel narrowboat but I’ve been itching to get a little GRP cruiser to explore the Thames estuary and the coast.

I’ve found one, and the price is right - almost free! It’s an 18’ Hardy motor cruiser (I don’t think many of these made it to the US?) with a Yanmar 2GM diesel connected to an SD20 saildrive. Looks like this same hull was available with a few options - outboard, outdrive or saildrive.

It’s been moored on the same bit of fresh water, never connected to shore power and never moved or run for at least 10 years. I changed the fluids, cleared the water intake with a brush, dropped in a good battery and it started on the button, gearbox seems to behave too, no water in the oil. Dog clutch which is weird. I’ve carefully removed the water sensor and it’s dry between the seals at the moment, I have no idea when they were last changed.

Question is about the saildrive diaphragms - I have about 20 miles of the upper Thames to cover to get it to be lifted out, antifouled and I’d also rebuild the saildrive with new anodes and diaphragm seals at the same time. I can’t get it lifted out prior to purchase though.

Never had a GRP boat with a saildrive before, what are they like in terms of reliability? Are the seals liable to have gotten hard, what’s the risk of them falling apart on the 20 mile cruise to dock? And when rebuilt, are they trustworthy for coastal cruising in light seas? I’d be getting an aux outboard before taking it out the estuary though!

Thanks for your help!

(just realised that the upper Thames probably doesn’t mean much as this is a mainly US board! Freshwater, I’ve got to cover 10 miles of almost canalised non tidal water, 10 miles of tidal flow but I’d be going with it. Engine would probably be running at medium throttle. I can do this bit in my 25 ton steel narrowboat with a 25hp diesel pretty easily so it shouldn’t be too bad for this little boat.)

[Tupaia]

I replaced my diaphragms after 13 years (recommended to change after 7 years) and they were as good as new. Salt water tropical conditions. I wouldn't worry to much about the seals but would keep an eye on exhaust, inlet pipes and water pump after such a long period of being laid up. Remember different anodes are used in fresh water.

[Jim Cate]

Best to carry a spare impeller for the raw water pump, or change it out proactively before you go. The rubber in the impeller perishes from age as well as hours of use, and it could fail suddenly. Otherwise, I don't see much risk in your proposed voyage.

Enjoy!

Jim

[LToast]

Thanks both. Yep, I’ll replace the impeller before I leave, definitely a good idea. Pumped water ok when I ran it up but it’s probably a rotten chunk by now!

Exhaust hose looks good but I’ll probably replace that when it’s out the water. It’ll be kept in brackish water - aluminium anodes?

Any foreseeable corrosion issues with not having anodes changed for a decade?

[Pete7]

There is a reason that boat is on the Thames, its ideal for leisurely cruising up and down the river and capable of short coastal trips in good weather. We had a Sealine 240 for a season with full planning hull. Wandered constantly as slow speeds due to little grip on the water. I would expect the Hardy to be better.

As for the 20 miles trip, I would would it. Keep an eye on engine temperature etc and if you can reach it, the top of the sail drive. They can get warm on a long trip but that's fine, hot is not.

Surprised it has a sail drive, stern drive I could understand, but if the price is good, ideal for pottering about. Used to take the dive rib up to Lechlade for a week to give it a good flush and get the salt out.

[Pete7]

Originally Posted by LToast

Thanks both. Yep, I’ll replace the impeller before I leave, definitely a good idea. Pumped water ok when I ran it up but it’s probably a rotten chunk by now!

Exhaust hose looks good but I’ll probably replace that when it’s out the water. It’ll be kept in brackish water - aluminium anodes?

Any foreseeable corrosion issues with not having anodes changed for a decade?

Yes go for al anodes but without inspecting them, no one will know. Aluminium drives are difficult to paint if its needed. Use a zinc rich primer and then lots of coats of either epoxy paint or internationals Primocon paint. Antifoul with none copper paint like Trilux in a tin. Depending on what you put on the hull, leave a 1" gap if it contains copper and Trilux the gap.

Pete

[LToast]

Thanks Pete. Yep, saildrive does seem odd on a boat like this, it seems that most of these had an outboard or Volvo outdrive fitted. The engine and saildrive bits are all easily accessible, I’ll keep an eye on the temperature. Price is right as it’s a token amount, the new landowner wants it gone, quick. I’m anticipating putting £1-2k into it for antifouling, service bits and a transmission rebuild though. If the gauge is to be believed, there’s only 1500 hours on the engine!

Had a look online and these hulls seem to be quite popular for coastal stuff in good weather, which is all I’d be using it for.

Originally Posted by Pete7

Yes go for al anodes but without inspecting them, no one will know. Aluminium drives are difficult to paint if it’s needed. Use a zinc rich primer and then lots of coats of either epoxy paint or internationals Primocon paint. Antifoul with none copper paint like Trilux in a tin. Depending on what you put on the hull, leave a 1" gap if it contains copper and Trilux the gap.

Reckon the drive will need painting but I’ve got time in August to go over the boat when it’s on the dry, thanks for the tips on anti foul, I’ll go for no-copper paint.

First GRP with an inboard I’ve owned so lots of reading to do!

[Kijit]

We have had a boat with a saildrive for 17 years and basically no issues. We changed the rubber hull seal after we had the boat for about 14 years (and don't know how long it had been in there before we bought the boat) and it was still fine. The drives are subject to corrosion, so keep good zincs on the drive. We have had no corrosion issues on our drive. As mentioned, painting seems to be a pain. This last haul out we put on several coats of Primocon and then a whole can of Trilux 33 and that seems to be working very well. The only other problem we have had with our drive is that we had to change the shaft seals as we were getting some water intrusion. I do hate having to haul to change the oil. Overall though, we have not had any problems with our drive.

[LToast]

Originally Posted by Kijit

We have had a boat with a saildrive for 17 years and basically no issues. We changed the rubber hull seal after we had the boat for about 14 years (and don't know how long it had been in there before we bought the boat) and it was still fine. The drives are subject to corrosion, so keep good zincs on the drive. We have had no corrosion issues on our drive. As mentioned, painting seems to be a pain. This last haul out we put on several coats of Primocon and then a whole can of Trilux 33 and that seems to be working very well. The only other problem we have had with our drive is that we had to change the shaft seals as we were getting some water intrusion. I do hate having to haul to change the oil. Overall though, we have not had any problems with our drive.

Thanks. On the Yanmar drives you can change the oil whilst in the water with an air compressor, it’s slow, messy and a pain though. Doesn’t seem to be any water ingress after running it in gear for half an hour or so, but I’ll change the seals anyway when it’s out the water.

I’ll do some research on painting, is it best to prime, paint then cover in Trilux antifoul?

[Uncle G]

If you are going to buy it without inspecting the bottom/saildrive/prop and then you intend to get an auxilliary outboard for going to sea, why not fit the outboard now and use it for the trip up the Thames?

The saildrive may be be OK at the moment, but 5 or 6 hours of motoring may cause something to fail. E.g. if the anode on the drive leg has corroded away years ago then there may be a problem with the prop that wouldn't show up until you gave it some work to do.

Or tow it with your narrowboat?

Once you can inspect it and put right anything that needs sorting then it should be fine for your intended use. We had a saildrive for years and went across the channel and down the west coast of France with it several times

[CarlF]

In the incredibly unlikely event that the water alarm goes off just keep going.. There are two seals. The boat’s not going to take on water if the outer one leaks.

A bigger risk is the 20+ year old cooling water hose springing a leak. Carry replacement hose or repair tape

Also replace the belt

[LToast]

Originally Posted by Uncle G

If you are going to buy it without inspecting the bottom/saildrive/prop and then you intend to get an auxilliary outboard for going to sea, why not fit the outboard now and use it for the trip up the Thames?

The saildrive may be be OK at the moment, but 5 or 6 hours of motoring may cause something to fail. E.g. if the anode on the drive leg has corroded away years ago then there may be a problem with the prop that wouldn't show up until you gave it some work to do.

Or tow it with your narrowboat?

Once you can inspect it and put right anything that needs sorting then it should be fine for your intended use. We had a saildrive for years and went across the channel and down the west coast of France with it several times

Thanks for the reply. I can tow it on the non tidal bit, the first 10 miles but I can’t legally tow on the tidal bit without a special license. I’d rather give it a good test on the non tidal (my partner will be following in the narrowboat!) as I’d rather anything fail there than on the tidal part, mooring is very difficult there.

Unfortunately the location (on a little backwater!) makes it nigh on impossible to do any serious work on it, and it needs a bracket fitting for the outboard too. I’m going to give the underside an inspection by feel next week as the water’s shallow enough to touch the bottom. The anode’s location looks like it’ll be easy enough to run my hands over, and I can check the prop edges.

I wouldn’t usually go through all this for a purchase but as i mentioned, the price is almost free!

Originally Posted by CarlF

In the incredibly unlikely event that the water alarm goes off just keep going.. There are two seals. The boat’s not going to take on water if the outer one leaks.

A bigger risk is the 20+ year old cooling water hose springing a leak. Carry replacement hose or repair tape

Also replace the belt

Thanks, yep I’ll replace the belt, hoses all look good but I’ll carry some spare exhaust hose and coolant hose. There’s a good stash of service spares on board too, filters etc still in their packaging which is a good sign.

I’ve had a look through the manual so I now know how it’s built, the engine is behind a waterline height bulkhead with a working bilge pump in there so even if both seals fail, it won’t sink.

[Uncle G]

When on the tidal part, it'd be a good idea to have a decent anchor ready to deploy on the Hardy. Just in case.

[Kijit]

Originally Posted by LToast

I’ll do some research on painting, is it best to prime, paint then cover in Trilux antifoul?

Two times I had the yard do our bottom and drive and they did not prime the drive. I always prime before painting, if the old paint is in poor condition. Is it absolutely necessary, I guess not, but it sure doesn't hurt and anything to help preserve the drive is good in my opinion!

[LToast]

Originally Posted by Uncle G

When on the tidal part, it'd be a good idea to have a decent anchor ready to deploy on the Hardy. Just in case.

Forgot about that bit actually! It’s got a decent size anchor and galvanised chain in good condition, need to buy a new rope though as it’s throughly rotten.

Thanks for the advice, I’ll probably be removing the drive from the boat to rebuild it whilst the yard scrape and antifoul the hull.