RE: 48
Pipe is a wet tuned pipe. Not a bad thing - will tend to keep the engine bay a little cooler and also will often keep the noise down. You will not see quite as much power as a properly adjusted dry pipe but if sport boating then the difference will be pretty close to negligible.
Thing I found on one of my boats was that when the boat got loud I knew it was not flowing water and shut her down - turned out I had some plastic over my intake.