Which keel?

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PhilipH

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Friend of mine is contemplating buying a 33-37 foot GRP boat - probably Jeanneau, Beneteau or Dufour. We were discussing relative merits of standard keel, shoal draft keel and lifting keel, re a Jeanneau 30-something which comes with any of the three options. Apart from the obvious advantages of shallow water, harbour and marina entrances what differences would there be to windward performance i.e. closeness of pointing and leeway, AVS and tenderness? Doesn't seem to be anything published - no comments on my search capabilities BTW.
Ta v much
 
Regarding AVS, look at the Southerly range. The 110 has almost no difference with keel up/down due to the huge cast plate embedded at the bottom of the hull. AVS is a massive 160 degrees with keel down (and over 150 even with it up). No affiliation - just an owner.
 
The relative performances will differ according to the design of boat, with some designs suffering much more in the bilge-keel version. There was a test years ago in YM of the Sadler 32 which showed that the best was, of course, the deep fin, followed closely by the lifting keel and a long way back by both shallow fin and bilge keels.

On the other hand, my HR34 with a shallow fin of about 1.6m (normal 1.8) has a performance which is comparable to the deep fin in moderate weather, and has similar sail-carrying power, and may have a slight performance advantage in light winds due to reduced wetted surface. I have only raced against sister-ships in light winds, when it was hard to see a difference, but in severe weather I would expect to make a bit more leeway. However, my shallow fin is rather deeper than what is offered on some boats.
 
Coastal NI/ROI with trips up west coast of Scotland. With is SWMBO who is a novice.

I think angle of heel is going to be very important and whilst pointing will be a factor, it's really about what performance loss there is between deep fin and shoal keel. I suspect lifting will be ruled out cos of potential maintenance issues but could be wrong.
 
I doubt if angle of heel will differ much, compared to the differences between boat shapes. If you don't want to heel much you need a beamy boat with a turn to the bilge, and a damned great engine because it won't sail to windward.
 
I'm not sure why the shallow fin did so badly, don't know the trials but I suspect there may have been other differences.

My Sadler 34 has the shallow fin and we recently had an opportunity to race against another 34, similar age, equipment and probably skills, and he couldn't point anything like as well as we could. His sails were considerably worse in shape than ours, which probably accounted for the main difference. Wind was up to F5 and it was a beat all the way, 20 miles or so. We finished about 20 minutes before him.
 
Your cruising area is the same as mine, there are very few places where an extra foot of draught will make any difference but a modern deep aerofoil in lead or composite with a properly designed hull will mean that you learn the real pleasure in sailing. If you intend to motor then it does not matter much whether you have bilge keels or a lifting keel under you. Our boat is a Finngulf 33, not unlike a X334 but better finished, these are sailing boats as are Beneteau Firsts and Maxis. However most cruisers just want to get about. A passage from Belfast Lough to Gigha takes about an hour less than in any Oceanis etc. but it is the joy of doing it quickly with the sails that really makes the real difference.
 
If you want the boat to sail then its got to be the deep fin option.
WRT the Sadler 32 tests the boats were identical (only one type/configuration made other than keel type afaik). Also angle of heel was reported to be less in the deep fin iirr.
Had a Sadler 32 so was quite interested at the time.
 
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