I did a little test on this and it proved out as I expected,
weight on a symmetrically hull ,added this much and it is just below the point it will roll 4 ft length
cut a foot off each end and added weight 2 ft in length
just a little over half te weight we are back at the point of rolling.
I expected that because the the ends are so much thinner ,but it is still close to half the length and half the weight puts you about the same place.
Ok I will stop with the styrofoam boats and go back to my corner
Ron

weight on a symmetrically hull ,added this much and it is just below the point it will roll 4 ft length
cut a foot off each end and added weight 2 ft in length

just a little over half te weight we are back at the point of rolling.
I expected that because the the ends are so much thinner ,but it is still close to half the length and half the weight puts you about the same place.
Ok I will stop with the styrofoam boats and go back to my corner
Ron