The current boat mechanic in 1.9 snapshots, makes no allowance for water flowing over varying terrain height . A boat can no longer paddle up 1 block height of water , without sinking . Does anyone know what the final mechanic should be . It's hard to report bugs , if no one knows , how the boat should function . A wood boat sinking is not realistic . Even a wooden rowboat filled up to top with water , is still buoyant ( Fact) . I suggest looking into adding a bilge pump to boat or some other mechanics like ballast . I have to call this a bug . because I can't understand 2 things - 1. A wooden boat with no buoyancy - 2 . A boat that can't go up 1 block height of water . Food for thought , the first submarine was a ordinary wooden rowboat turned upside down , weighted with rocks for ballast . As an easy compromise , the boat capsizes and sinks , click on the boat , it turns right side up and floats to top . Without proper boat mechanics in the game , boats may be useless .