Water help with lab

Hey, So my yellow lab is 4 months old and is obsessive about water. I took him swimming a couple of times and had the same result. He gets in the water and enters his own world; he doesn't listen to any command and is only worried about the water. He splashes around drinking as much water as possible until he is so full he throws up. I have tried putting him on his chord and using his whistle (both of which he responds to very well on land) neither having a positive out come. In my backyard he will bark at the pool and the hose cause he knows there is water in them. If anyone has any suggestions I am mostly concerned with the lake and getting him to stop drinking all the water. Thanks, Pete