Max Displacement is more of the designer's estimate of the upper end of the ideal displacement range for the design. Going past that point, the paddling characteristics start to degrade. How much degradation depends upon the particular design.

A true max displacement would be the total volume of the kayak submerged, but that's usually not a practical way to paddle. :)

Ross

: Hello,

: I've asked Tom Yost what the max. displacement for his sea tour 13
: is and got answered 275 pounds at 4 3/4 inch.

: No call me ingratefull, sceptical or even plain rude, but this
: seems incorrent.

: I've checked a couple of other designs, Nick's great auk 14, Ted
: moores Venture 14 and CLC's shearwater 14. All being a foot
: longer and both the auk and the shearwater have wider beams but
: they both don't even come close to 275 pounds.

: I even did a quick test in kayakfoundry and it's hard to get the
: displacement below 225 at 4 3/4 inch.

: Is there a quick way to calculate max. displacement for an existing
: design ?