Originally Posted by Rohan
In most of the arrangements described in this entire thread, all the ballast is in the long swing keel. But doesn't that still require significantly more weight than a standard fin keel with a bulb? Because the nice thing about a bulb is that concentrates the weight as low as possible.
As you can see on the picture that kind of swing keel are also kind of bulbed in a sense that they ate much more heavier on the bottom than on the top. Look where the CG is:
Besides that, typically on a boat
that has a swing keel as an option to a torpedo keel (much more performant than a bulbed keel), the draft
on the torpedo one is about 2/2.20 and the draft
of the swing keel 2.5/2.7m. I have seen that on most cases with this draft configuration the swing keel and the ballast it has is normally just a bit less than the one on the torpedo keel for generating the same RM.