The volume has little to do with the design displacement/payload.
Many play boats have plenty of volume above water near the paddler, but very little at the ends. Compared to something with the same volume but with a more even volume distribution, the two designs will paddle very differently...
Also, true that boats with higher design displacement and overall volume will tend to want to stay in the hole more for the same paddler compared to a "smaller" boat. But that is good for surfing and flat spinning (not so good if you are stuck in a hole against your wishes -;))
I paddle the Axiom 8.5 and am at the top weight range for it. I can feel that a bit more volume will make it surf and spin better. However, being so deep in the water makes it very slicey and I can just carve out of waves and holes where with the Fuse 64 I would be more inclined to stay in... Also, the added width of the Fuse makes it very stable sideways, requiring added effort to edge on green water (but works great with foamy water where you lose buoyancy)... So no clear cut... What's good for one use is not so good for other uses...
Hardshell Kayak Sail Rigs
Full Size Sail Rig
Bent Shaft Canoe Paddles
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