Hi, Thank you for getting in touch, And telling me about this bug. I have found out what the problem is and i am now working to fixing it.

[Google Translate]
Hello! I really liked your map, so I put it on my Murder server. But the players found a bug that severely spoils the game. When you are on the water, if you hold down ctrl + space, you can somehow "walk" on the water without taking damage. If it is not difficult for you to fix this, then I and the players on my server will be happy.

I love this Playing It Now!