You can take an existing quadbike and drive on water, as shown in this video:
If you used a quadbike with 4 wheel drive, bigger tires, a mud-tire tred, some safety floatation, it could work very well. The tire below works well for pushing water. The bike would have to be designed to withstand saltwater, which is probably the real hard part of this idea. But it could be done and would be fantastic to drive around the ocean at high speed. So commuting from your floating home to someplace on land could be very fast and a lot of fun. If you are not needing to go far, a 4 wheel drive electric might be easier to make resistant to salt water. Also, if you have a solar powered floating home you would always be able to charge up an electric bike.