cAN A privilege 39' sit on its keels

[yan23]

can a privilege 39' sit on its keels on a sandbar. let the tide go out.

any owner know this ??
will the keels break thru hull???

not asking about props and rudders. i got that figured out.

my plan is put hull shaped blocks of wood under the hulls ,2 on each hull.
they are made so 24'' of the hull sits on each block.which sits on level sandbar.
i wait for tide to go out and remove and replace my sail drive unit.
one each day.

[fourlyons]

I don't have personal experience with this boat, but every boat I've ever seen in a yard sits on it's keel (keels). The stands are only to keep it upright, not to lift the boat. Most cats I see don't even really bother with stands.

[Jeannius]

I know the boats are not exactly the same but I beached my P435 many times without a problem.

Not sure I'd take on changing out a saildrive between tides though. I had enough trouble getting reluctant lower seals out and new ones in on a tide up in Maine and I had a decent tidal range of around 10 ft. Of course you are probably a much better mechanic than me with a better toolkit.

[toolbar]

Judging from these photos here, standing on the keels shouldn't be a problem: https://www.yachtworld.de/Boote/1992...ge-39-3202747/

But I wouldn't want to change a saildrive with the possibilty of time running out. What is your plan b if something goes wrong? And when you replace stuff on a boat, the only thing you can be sure of, is that something will go wrong/will not fit exactly/will be missing.

Breaking the head of a screw when you have half removed the saildrive is anoying in a yard, but on the beach with the water rushing back???


Paul

[Cadence]

Changing on a tide sounds risky. It can probably be done, it's the what ifs that would scare me. Sound like it could be costlier than a haul out?

[Orin]

Originally Posted by yan23

can a privilege 39' sit on its keels on a sandbar. let the tide go out.

any owner know this ??
will the keels break thru hull???

not asking about props and rudders. i got that figured out.

my plan is put hull shaped blocks of wood under the hulls ,2 on each hull.
they are made so 24'' of the hull sits on each block.which sits on level sandbar.
i wait for tide to go out and remove and replace my sail drive unit.
one each day.

Every boat I’ve blocked up has had at least half its weight on the keel. As someone mentioned before the blocks and stands are really there more for support and to make sure the hull doesn’t sag or squat. The most you can crank up on those with is about 1,000lbs a stand... and it’s bad practice to reef of em. Just synch them up really... probably 250lbs force on each stand tops. My C&C would be blocked up with 6 stands (fin keel mono) weighing something near 8000lbs I’d figure probably 6,500 of that was the keel resting on the stack of 2x8s below it. Granted 3000 of that is ballast directly on the blocks. It’s nice how most of the remaining weight is the part that’s sitting on the bottom. I would think the picture would be quite different with a cars worth of weight on deck.

If you look at pictures of the privilege 39’ blocked up, you’ll see that few stands are used and figuring with 250# on each they’re just there to add some stability.

If you add blocks just be sure they’re spreading whatever weight you put on them.

If it was my boat on a nice fine sand bottom with no wave action I’d just rig some spars for and aft to make sure she will sit evenly on her keels and let the tide set me down.

[Fore and Aft]

Yan23 if you do beach your cat to replace your sail drives make sure you set up a time lapse camera on a tripod. That's going to be one YouTube video I would watch. How are you going to stop the water getting into the boat if you do not get the leg back on in time?
Cheers

[Huey2]

I had a privilege 39 that I sold about two years ago. I purchased two 2005 MD2030 Volvo diesels with sail drives, wiring harness, dash panel / gauges, boot rings and etc. as back ups. They are sitting in my pole barn if anyone is interested. Replacing a sail drive between tides..........would your insurance co. provide coverage if anything goes wrong? One hoist fee while you replace both drives and boots sounds better. Good luck!

[Heath68]

Try here.. Jim is very knowledgeable about the Jeantot/Privilege 39 having had one for years.. a pic on the front page answers your question www.multihull.tv

[Nani Kai]

Originally Posted by yan23

can a privilege 39' sit on its keels on a sandbar. let the tide go out.

any owner know this ??
will the keels break thru hull???

not asking about props and rudders. i got that figured out.

my plan is put hull shaped blocks of wood under the hulls ,2 on each hull.
they are made so 24'' of the hull sits on each block.which sits on level sandbar.
i wait for tide to go out and remove and replace my sail drive unit.
one each day.

Hmmmm.....setting aside the "what ifs" noted up thread (which would also be a HUGE concern from my perspective) I have a coupla other questions.

A Google search says a privilege 39 draws 3'6" of water. In my experience the tidal change in the Miami area is about 2.5-3'.

So you find a nice predominately level sand bar that has 4' of water over it at high tide. You motor up, toss the hook and wait for the tide to go out. It's now all the way out and there is a foot of water still on the sand bar.

Even if you waited until you paired up a tidal cycle with a historically maximum high tide and a historically minimum low you're still looking at maybe a 4' change. Which barely exposes the sand bar.

Keep in mind that the lull between tides doesn't last very long, maybe an hour and then it starts to flow again. So even under the best circumstances you would have very little time to do the exchange before your feet started getting wet.

Second question: I don't see a way to put four 24" hull shaped wooden blocks under the hulls and keep them there while the boat is floating. If you tried to submerge a cube of wood 1' wide x 1'tall x1' deep, much smaller than the proposed blocks you mention, it would push back with 64lbs of force. Once in position it would try to return to the surface with the same amount of force. Anything's possible I guess but I think you'd run out of tidal time just getting the blocks into position.

[fourlyons]

All good points Nanni Kai.

Except the point about one cubic foot of wood resisting being submerged, you forgot that wood weighs something too. It would be much harder to carry a cubic foot of Ironwood to the boat than it would be to push it under

Originally Posted by Nani Kai

Hmmmm.....setting aside the "what ifs" noted up thread (which would also be a HUGE concern from my perspective) I have a coupla other questions.

A Google search says a privilege 39 draws 3'6" of water. In my experience the tidal change in the Miami area is about 2.5-3'.

So you find a nice predominately level sand bar that has 4' of water over it at high tide. You motor up, toss the hook and wait for the tide to go out. It's now all the way out and there is a foot of water still on the sand bar.

Even if you waited until you paired up a tidal cycle with a historically maximum high tide and a historically minimum low you're still looking at maybe a 4' change. Which barely exposes the sand bar.

Keep in mind that the lull between tides doesn't last very long, maybe an hour and then it starts to flow again. So even under the best circumstances you would have very little time to do the exchange before your feet started getting wet.

Second question: I don't see a way to put four 24" hull shaped wooden blocks under the hulls and keep them there while the boat is floating. If you tried to submerge a cube of wood 1' wide x 1'tall x1' deep, much smaller than the proposed blocks you mention, it would push back with 64lbs of force. Once in position it would try to return to the surface with the same amount of force. Anything's possible I guess but I think you'd run out of tidal time just getting the blocks into position.

[Nani Kai]

Originally Posted by fourlyons

All good points Nanni Kai.

Except the point about one cubic foot of wood resisting being submerged, you forgot that wood weighs something too. It would be much harder to carry a cubic foot of Ironwood to the boat than it would be to push it under

Of course, Ironwood! Silly me. What was I thinking? Must be the accumulating number of birthdays.

Let's see, a solid chunk of ironwood, say 2' wide by 2' long as the OP suggests, by however deep the keels are, say 14", make it 12" so the math is easy, that's 4 cu ft. They will each displace that amount of sea water which will buoy them up with 256 lbs of force so the blocks would have to be heavier than that to sink, how about 275 lbs each?

Okay, I see it now. Get 1100 lbs of ironwood, cut it into four pieces, throw them over the side, then drag them under the boat and wait for the tide. How simple!

The work is done in record time, the boat is all ready to go. All we have left to do is get 1100 lbs of ironwood off the bottom, into the boat and Bimini here we come!

Simple problem, simple solution. Gotta Love it.

[Cadence]

Originally Posted by Nani Kai

Of course, Ironwood! Silly me. What was I thinking? Must be the accumulating number of birthdays.

Let's see, a solid chunk of ironwood, say 2' wide by 2' long as the OP suggests, by however deep the keels are, say 14", make it 12" so the math is easy, that's 4 cu ft. They will each displace that amount of sea water which will buoy them up with 256 lbs of force so the blocks would have to be heavier than that to sink, how about 275 lbs each?

Okay, I see it now. Get 1100 lbs of ironwood, cut it into four pieces, throw them over the side, then drag them under the boat and wait for the tide. How simple!

The work is done in record time, the boat is all ready to go. All we have left to do is get 1100 lbs of ironwood off the bottom, into the boat and Bimini here we come!

Simple problem, simple solution. Gotta Love it.

Seems like it's getting a bit juvenile? He should use balsa.