Centerboard ropes in shallow water

[Sean McGuire]

I was wondering if anyone had come up with a way to safely sail in shallow water where there are sandy shoals to contend with. I would like for my centerboard to be able to come up if I wander into a shallow area. I was thinking I could rig up a bungee cord to the uncleated centerboard downhaul rope to keep tension on it under normal deeper water conditions but allow the centerboard to rectract if I hit a shoal. Any thoughts (or drawings or photos) on how I might rig it would be appreciated.

Sean McGuire

[Roger]

I have no photos or drawings, but later versions of the DS II had a shock cord built into the system just for this purpose. I'm not sure exactly where it went, but if you read the specs and measures document in the handbook on this site, I think there is a reference to it.

The retrofit however is to place the the downhaul block at the midpoint of a short bungee cord, and reattach the hooks of the bungee where the block usually anchors. This is at the top of the cuddy. The doubled bungee is needed to have enough strength to pull the bungee back down when it kicks up. This would be especially good when there was a risk of knockdown from excessive wind.

I never did do this retrofit, but would just sail in shallow waters with the downhaul uncleated. If I hit something, it would kick up, but the weight of board was often enough to allow it to drop back down.

[Roger]

Sorry, I gave the wrong source information regarding that bungee cord. It is actually in the DS II manual, not the specs and measures doc and it reads as follows:

*(As of August, 1975 a 10 1/2" piece of shock cord has been added to keep the forward c/b pendant
tight while the c/b is down)

[SUNBIRD]

That short pice of bungee cord fitted to the 1975 and later models of the DS II was to prevent the upline cable from getting jammed in the cb trunk. It was run between a becket on the block attached to the ss cable that pulls the CB up, and an eyestrap just aft of the mast. This keeps some tension on the up line cable when the board is down. There should be an archived thread about this subject, look for it somewhare in the years 1999-2001 (approx). Someone mentioned that they actually replaced the downline with shock cord/bungee cord and then used the upline to hold the board at what ever depth needed. If the CB hit bottom it should overcome the pull of the bungee cord and pull up. I experimented with the idea, but never really got it to work. If it was loose enough to allow the Cb to easily kick-up, it wasn't tight enough to pull it back down. A few years ago I was talking to an owner of a DS III and since the CB rigging is basically the same, he was also trying to come up with a better way to hold the CB down while still able to kick-up if he hit bottom. He was researching a kind of camcleat that would automatically release the line if the pull exceeded the preset limit. This was an "off-the-shelf" cleat, but I was out of work at the time (as was he) and so did not pursue the cleat. I think it might be called a "servo-cleat"? The idea was that the cleat would release the hold-down line when the CB hit bottom allowing it to easily kick-up.
In the mean time, I just sail with the line untied if I'm in shallow water. The sideways pressure on hte CB while sailing will pretty much "lock" it down without the line, and of course it will then kick-up if it hits bottom.