I did a search on this and there is very little info. Any experience with Aquapower (I think the old HPI?), GGB, Corsa, etc? I still want a deep sound and of course not put too big a dent in performance, if this is even possible? Aquapower claims "approved by Mercury"...anyone have these? Thanks in advance, Dave

The largest noise reduction I have ever heard was from a set of GGB's that a freind added to twin 750's. He said he had no loss of power.

I've been running the Imco Gatlins for 4 years now. Havn't had any issues with the noise police, "knock on wood", and no power loss that i'm aware of.

http://ggb.ca/index.php?id_category=...oller=category

I put in the GGB inserts. No loss that I can tell, and dropped the noise but still has a nice sound. They do best in wet exhaust. When dry, they bark like they are not in there. you can really tell when the water hits them, tone mellows out and sound level drops.

I have a new pair of Gibson Marine tips you may be interested in. Your PM box is full.

I installed GGB inserts this season, very pleased with them. Nice deep sound.

I'm running the Gibson Clamp on's on my 700hp 524 with headers. I like them because they don't impinge significantly on the diameter of the exhaust and they still keep me legal. On top of that they sound really nice.

GGB-super muffler with virtually no power drop. When I had GGB's (before I lost one) my boat went no slower with or without them (100 mph Baja 272 with 1100 hp). I bought Gibsons to replace the GGB's because I needed them for a planned vacation and boat has never felt like it should with them on (missing some rpm's), going to pull them back off after my next vacation is over and try open exhaust for a day and probably get another set of GGB'S coming, Smitty

I have just bought a pair of custom built silencers from Aquapower for my 454 with Eickert headers and dry to the tip tails, nicely built all in 316 and great service from Paul at Aquapower, he was really attentive and sent me PDF's of the proposed design then turned the job around in a couple of days. I am just finishing off a rebuild so hope to have the boat back in the water in the next week, I 'll let you know how it sounds.