I would like to jump into this conversation.
Because of our proximity to major multiday river expedition opportunities like the Grand Canyon, and Smaller more technical stuff like the Upper Animas, We decided that long straight water line was more important than a rockered design. That has shifted slightly with the introduction of the Royal flush that has a more rockered section on the ends, but still has a bit more capacity than a daddy cat with a heavy load. We were trying to provide a good all around boat for these two extremes. Keeping in mind that cargo takes priority over empty performance, because the majority of our customers purchase these two boats for multi day trips. That being said, have a look at draft VS load
for some of our most popular cataraft tube models.
The idea is that the weight is evenly balanced so the tubes sink evenly in the water, and the inch measurement on the left is determined by the weight that each boat can carry, in the particular column.
We did this to help our customers make informed choices on which boat to purchase. The Royal flush has become our best over all multi day cataraft, that is still nimble enough to do something like the upper Animas.