Danish yacht manufacturer X-Yachts has been explaining why it designs "L" shaped keels for its cruisers, and torpedo "T" shaped keels for its performance yachts range?
Apart from an obvious advantage of the L shaped keel shedding seaweed and lobster pots over the T keel, there are more design considerations that are made.
The main difference is that the centre of lateral resistance is further aft on a T keel in comparison to the more conventional L keel.
The Xc Range has been designed to be more forgiving on longer passages, therefore the sail plan is further forward, suiting the L keel design.
With the Xp Range, there is a desire for optimum upwind performance. One of the ways to achieve this is by maximising the fore-triangle, which moves the centre of effort aft, requiring a keel choice with centre of lateral resistance further aft. Simply moving an L keel aft would not work as the bulb (ballast) must remain in the same location fore and aft.
