water over transom

[jobu]

I have a 23' Sceptre and recently noticed a little more than a neusense amount of water coming in over the transom and also notced the drain holes don't seem to be low enough to drain quickly. I was reading the post about the rolling in an 8' see when the writer made note of this too.
What is the easy way to remedy this?
Also I have two cylinders glassed into the stern. They look like coffee cans with spark plugs coming out the top.(hehe) What are they for?