Love it! But maybe change the effect to resistance while drinking a Potion of Defense. Here is an idea of what it could be like. Lvl 1: Resistance 1 for 2:00 Extended: Resistance 2 for 5:00...
When you break a waterlogged block, it should have the "drip" particles coming out as you mine it. This would look really cool and it would make my day seeing it in real Minecraft.