So took the boat out this weekend and ran into a problem. We had been cruising around for about 20-30 minutes when I ran into some shallow water. Wasn't a huge deal just back out and kept going. A couple minutes later I noticed white smoke coming from the water behind us and a small amount coming from engine compartment. I pulled the engine cover up and noticed the water level in there was really high and had the bilge pump on but it would not keep up. Luckliy I was near the ramp so I put the boat on the trailer and gave it a looking over. I noticed that the exhaust flaps were missing on both sides which would probably explain the water in the engine area but I'm not sure what was going on with the smoke.

So two questions:
1. What size exhaust flaps do I need for a 98 outback and where do I get them?
2. What do I need to be looking for concerning the white smoke? The boat ran fine, wasn't getting hot and had plenty oil pressure so I'm not sure what to look for or what to do.

Any help would be much appreciated.