Needless to say post the photo.
My guess is that the keel being down increases then leverage of the weight.
Has anybody calculated drag forces on a standard Atalanta? I believe it can be done by a towing one using a newton meter, or hanging scales. If we graph this against speed we would to see an initial upwards curve showing the wave forming drag that defines the hull speed then a kind of levelling off as the planing comes in.
Be a good article…