I have shot a couple from that kayak but shooting with your legs straight out and not being able to pivot very well isn't the most productive way to shoot birds. I also don't like paddling with a shotgun laying across my lap. If it slides off my lap it's likely gone for good. Last weekend I took that photo on the bow because my kayak was the only dry place where I could lay my gun.

However, I have shot a number of times from the boat below. I do that when the areas I hunt are flooded and the birds move from shore to floating mats. I use a paddle to approach the mat. The mats range in size from 15' in diameter to perhaps as much as 100'. They are peat mats from the bottom of the lake that have broken loose and are now floating on the surface. I lay the gun across the bow and sit in the very front seat. Sometimes they flush as I am approaching, sometimes not until I bump into the mat and stand up. A number of factors influence how approachable those birds are including the density and height of the vegetation growing on the mat. I shoot more sitting than standing but it is easier to pivot on a boat seat than in a kayak.