I do not think that attaching floats to the P2V skids will not work well.
A tiny wave will tip it over....
Hand catching:
If you get a neck strap for the RC you will find than hand catching is really easy.
Start with bringing the P2V eye height, walk towards the P2V and grab the skid with your right hand.
Use the left hand to shutdown the P2V (left stick down)
When you feel comfortable with this move, you can skip the "walk toward the P2V" part.
Bring the P2V as close as possible and just reach for it.
Hand launching: (a bit more tricky, but also easy)
Put the P2V on the deck, and do the usual stuff when getting ready for a normal launch except starting the props.
When the P2V is ready to fly (GPS okay, WiFi okay) pick it up at the skid with your right hand, and hold it in front of you.
Now the tricky part. Use your left hand and start the P2V (I've got big hands and can do this with my thumb and index finger)
When the props are running, and ready for takeoff, use your left hand to throttle up.
I always tilde the P2V a littler bit away from me when hand launching.
For hand launching you will need a neck strap.
Not sure how good you are in RC, but the best way of doing all the above moves are with the back of the P2V facing you.
Why?? If you suddenly need to move it, left is left, right is right etc....