My first thought was killer whale. Not sure now though. Can't see white on any of them but not sure if you would be able to from that vantage.
Maybe a really young one, but orca typically have bigger, taller and straight dorsals, males anyway. Maybe small female? My first thought at seeing that pic was Dall's porpoise, so depending on where that was taken he still could be chilling way too far offshore in a kayak, in the middle of killer whale county. Some orca only eat fish. The meat eating ones look at a Dall's like you and I look at a pulled pork burrito. They toss'em like burritos too.
Nope.
Make mine a 45' Hatteras please and thank you. One of those decked out for fishing Waverunners I could see even, but not an amateur kayak.