Leeboards?

[JeffM]

Just a thought: Could a Core Sound 20 work with leeboards rather than the design centerboard? I'm about to begin building a CS20 now. I first became interested in cat ketch beach cruisers when I admired the Sea Pearl 21 (by Marine Concepts) I have read good things about them (performance of assymetric boards, reduced heel caused by weight of raised windward board, ease of maintenance), and seen no drawbacks except asthetics.

Jeff Michals-Brown

[Stump]

I think any boat could work with leeboards. I have seen lots of designs from England and Europe that use leeboards as actual legs for keeping the boat upright in low tide /overnight/camping situations. they were around long before centerboards, (I think :roll: ) Some of the European designs have two "outside centerboards" which I think could also be called inside leeboards. Jim Mc...something, uses only one board on all his designs. I'm not convinced that you actually need two for sailing purposes. On the little skiff I built I used only one. It is designed more like a really off center centerboard, being that it locks down and is supported on both sides of the board. I haven't played with it enough to find out if there is a difference in tacking.

[Frank Hagan]

Do you need to raise one lee board when you are on a tack? (I guess you would raise the one to windward to prevent the drag it would give you).

If so, that's the only disadvantage I can think of. Some of us enjoy "pulling strings," so that may not be much of a disadvantage.

In this case, I'd ask Graham's advice also. There may be a design consideration we're not thinking of.

[JeffM]

You raise the windward board, which has the added benefit of placing extra weight on that side to reduce heel (the leeward board, being submerged, is approximately weightless).

I expect a Core Sound would need substantial side reinforcment to accept leeboards, and maybe there'd be little gain in interior space (from loosing the CB trunk), since the center thwart is structural, and also supports the mizzenmast step.

[mustangermatt]

The Groote Beer (dutch for Great Bear) that I sailed on as a sea scout was a large dutch leeboard cutter. If sailed correctly her performance was suprising.

One annoying tendancy of leeboards is that they sometimes float out away from the side of the boat in light air, then bang back in on the next swell.

As far as using them on a coresound my first question would be what would you really gain?

Don't get me wrong, I probably like leeboards better than most, but the coresound has a very good system already which is easier to build. Remember that one of the areas of highest stress on a boat will be around the keel/centerbaord/leeboard. With a centerboard you only have to build the supporting structure once instead of twice.

If you do end up using leeboards look at a dutch "botter" first. There are a few sites with them on the web. These where the height of the commercial leeboard vessels. You will notice that the leeboards are high aspect ratio (long) not the ridiculous fan shaped things you see on most american copies (sea pearls for instance) :-). And then get the offsets for a naca foil and loft your boards to that. A flat leeboard (or centerboard or keel) is in a constant stall with turbulance on the windward side where the lift is supposed to be coming from. Very inefficient. Fore a fast boat like the coresound you owe it to yourself to at least use the technology the Dutch shipbuilders used 100 years ago :-)