Minimum water for a controllable Mac

[solentboy]

Hi

Any thoughts on the minimum water depth required to be able to control the MAC 26M. I was going to practice in some open water next time out, but thought I would ask wiser and more experienced Mac owners as well.

My Marina dock dries out at low Spring tides. I have had my Mac for 2 months now and I have come in and out with rudders full down and about 12" of daggerboard. Often get a cross wind going down the narrow channel (between other boats!).

Any thoughts on the minimum amount of water I could get away ? Any experience of using the rudders partly down ?

Cheers
Kevin

[John Christian]

3 feet should allow you full rudders 3/4 cb and motor down.

Last season our slip started out just under three feet and allowed us to dock with full rudders down and 3/4 CB. Did not have any problems even in stiff crosswind. By August water level had dropped below 2 ft forcing me to raise 1/2 ruddder, most of the CB and trim motor up slightly. Docking in a crosswind was not fun and most times I walked her in from the end of the dock.

Moved to new marina this year and have 7 feet under the boat, no issues.

JC

[Boblee]

Would be a bit careful having the rudders only 1/2 down John it puts a lot of pressure on them especially if you manage to hit something hard the leverage would be enormous.

[tangentair]

Rudders down (fully or none at all - just breaks something any other way), one or both help. but the most help is from the daggerboard as far as I have experienced. I start with it down 8-12 inches, I do not actually measure, just drop it some. It moves the pivit point a little forward and gives some control. But without wind, there still isn't the control of a full keel boat. And with wind and the high freeboard for it to push on, well I use spring lines a lot and take things slow and easy along the dock and get up some speed as soon as safe. I really haven't tried driving around in a crowded marina, but where I launch there is a sunfish racing club and I have been know to utter the disparaging remark quite often.

[cuisto]

Check out THIS MARINA, My 26x is the 1st boat in from the lake, southern most slips. To get out of the marina we would have the CB down just a bit, 1 rudder down horizontal, tied off in this position, slowly back out, punch it into fwd just to straighten out then back off and putt putt fwd to clear the break wall.
once in the channel, yank up the rudder and drop a loop of bungee cord around it (this loop is tied off to the stern rail and always at the ready). Blast out the channel at full throttle when it is clear at it is far easier or 1/2 throttle with some traffic. This is a small marina where we mostly knew each other and people knew how tricky this boat could be in this manoever, I was usually waved on by the more manoeverable boats.

The Channel leading to the marina is about 18-24" deep the maina entrance changes all the time as wake and rough weather off the lake drag sand around but in the center of the opening aprox 24" and in my slip the bow rested on sand while the stern had about 4' of water.

With some practice you can do most anything but I was also lucky that the marina operator gave me the first slip in from the lake making it a bit easier to glide in. There is a hunter 25 on the far side that seems to have no problem at all.

Water in the channel last year droped to about 18" in the deep spots and by late august i could no longer get out. Thids year i have a new maina with 12' below me.

[tangentair]

Looks like you had quite a lot of shallows to manuver through before you got out. I am surprised that Hunter had less trouble. His draft should be about 6 inches more than yours. Anyway I agree that it is better to power through as fast as practical.

[RickJ]

Any thoughts on the minimum water depth required to be able to control the MAC 26M. I was going to practice in some open water next time out, but thought I would ask wiser and more experienced Mac owners as well.

Hi Kevin

I find with my that as long as there is depth for the rudders there's no problem. It helps to keep some centerboard (dagger board in your case) down, but it doesn't need to be lower than the rudders. That's fine down to about 1m depth, but if I get to .8m the rudders start dragging - not so good. The Medina gets like this at low tide.

With care it can still be handled below this (so long as it's not too windy) by raising the rudders, and lifting the CB/DB so that it doesn't ground. As already mentioned, rudders must be either up or down, never half-way or something will probably break. Keeping as much board down as you safely can is a big help with control in this situation.

The limiting point after that is when the OB starts dragging. You can trim it up a bit in the extreme, but when your prop is in the mud (or worse still rocks ) you're about finished.

Cheers, Rick

[ronacarme]

I piggybacked a DIY shoal rudder ( a suitably shaped piece of pine one by eight) on a longer stbd rudder pivot bolt on my X several years ago (search prior posts re "shoal rudder" for details). Depth about the same as the OB. That plus 3-5" of CB line out gave adequate ( tho not as good as stock rudders down) forward steering control. Don't know if one could add a similar shoal rudder on an M.
I run with stock rudders full up or full down ONLY, to avoid breakage. Lack of steering control in water too shoal for full stock rudders down led to adding the piggyback shoal rudder. Good luck....Ron

[tangentair]

I piggybacked a DIY.....(search prior posts re "shoal rudder" for details). ..... down led to adding the piggyback shoal rudder. Good luck....Ron

Gonna need more than luck, as best I can tell, you posted the description some time around 7/1/04 and the earliest post that I could get searching was 7/4/04. You referred to your earlier post in it also.

[ronacarme]

If anyone wants details on the shoal rudder, I believe I still have the original sketch someplace and would be happy to mail you a copy. Ron

[Billy]

Back in '01 when I ran a 25 hp engine, I built a set of shoal draft rudders out of stainless that worked with the factory brackets. They ran 10" deeper than the bottom of the hull---about the same depth as the prop. Turned out, if I needed them it was to late to deploy. After a year with the bigger engine (and bigger prop), I discovered I could steer through the shallows better with the engine trimmed up and so removed the extra rudders. But here's the pics showing how the offset cleared the factory rudder lines. (Also, started sailing much deeper water. )





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These worked OK, but could have used a little stiffening. Now, bungee cords and big prop manage to handle the skinny water.

[Morimaro]

On a Mac Rally a few years back four boats managed to manoeuvre out of a harbour in France on a falling tide (nearly bottom of tide) and with all foils up and motors down about 30 degrees we managed to get to deeper water about 50-100 meters away from our mooring buoys. The motors did not give much drive but shot water for a long way behind the boats. We reckoned there was max 12" below the hull and dropping.

Having grounded parts of the boat at various time during my 10yrs around the Solent, I use rule of thumb, CB/DB down needs 2m water, rudders down need 1.5m of water and just engine fully down needs 1m of water: thats all with sand or muddy bottom, if there any chance of rocks don't even think about less then 2m+.

With cross winds/tide on mooring, rudders down and preferably full CB/DB but at least down to match rudders.

Cheers
Morris
Yarmouth IoW