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   Tom has a ski boat powered by an Indmar 5.7 liter fuel injected V-8 engine. He wanted to replace his leaking fiberglass mufflers. We selected the 9072-PR inlines for his application. Tom called after 3 weeks to say thank you, the engine is quieter and performs better now than it did before. This kind of reponse is always a thrill for me. Thanks Tom. August 2014

   Anthony has a Cigarette with water reversion issues both with and without his existing mufflers. We ran one engine with open exhaust at idle on the trailer (with a pretty good water supply). The tailpipes have a groove just behind the header joint where water collects and it was full. A set of APL Clamp-On mufflers were installed and the engine was idled again for quite a while. The engine was then shut down and the mufflers were removed for inspection. The pipes were completely dry. At least for his engine water reversion was stopped just by using Aqua Power Ltd mufflers. This has been suspected for quite a while but never demontrated before. It will be interesting to see if this is true for all boats or just his. July 2013

   Jeff ordered a custom pair of our 4" Clamp-ons for his 496 HO. After a pleasant run on New Years day he sent an email saying, "Paul, the mufflers are fabulous! I couldn't be more pleased. The nearly 10db less is just what I wanted, and the tone is very nice. They look beautiful, too." Jeff, thanks for the great feedback.

   Rory in WA has an Outerlimits with dual 1550 hp Sterling engines. He installed our high power 5" Clamp-Ons (9053-75-S). Rory sent an email saying "All I have to say is WOW!!!! It's a completely different boat with the mufflers on. Everyone including the local authorities couldn't believe what they were hearing! Your product was beautifully crafted and performed above and beyond expectations!" Thanks Rory.

   Kevin in PA has a 37' Outerlimits with dual 600 SCIs equiped with 420 Mega Blowers (650 hp). After his first day out he wrote, "All I can say is WOW!!! They worked better than expected. They took the "bark" out of the sound. Throughout the RPM range the noise was greatly reduced. Everyone of my neighbors at the marina has asked me what I did to the boat." Thanks Kevin.

   Peter S. from Massachusetts needed to quiet a pair of Yanmar 300 hp turbocharged diesels this year (2010). I was uncertain if our technology would help so I sent him a muffler to try, he said he was amazed by the sound difference it produced. Peter purchased a pair of 9049-75s. After over 2 weeks of running twice a day he reported no performance change and the exhaust is so quiet that he now wants to soundproof the engine compartment. He commented that young children no longer complain about the exhaust noise from the engines. (I guess the turbochargers made a whining sound that hurt their ears). Thank you Peter for the wonderful input. Peter called again in early spring after a full year of service in salt water and said that the mufflers still look new after a mild cleaning except for a slight discoloration found around the the clamp-bolts which he easily removed. He also said that the ability to communicate with passangers has been greatly improved. Thanks again Peter.

   Mike C. of New Jersey purchased two sets of 9047-PRs for his 31 foot Sonic with twin 496 HOs and Captains Calls. Mike says they are 'fantastic', no power loss at all and he can carry on a conversation in a normal voice, at least up to 38 mph. He said they have a great sound, 'mellow' and you still know there are engines in there. Even his wife likes them. Mike told me they are all that I claimed. He called me back 5 minutes later to say I can report his comments here and if anyone wants to ask him directly about the mufflers then I can pass on his phone number. Thank You Mike for the great feedback.

   Aqua Power Ltd mufflers carry Steve Haynes to victory in the 2008 Vette Magazine Year One Challange. See more on the Gallery page.

   Good news, we have changed our 4.5" & 5" Clamp-Ons to give even greater noise reduction. The new 4.5" standard clamp-on (9051-PR-S) was tested on a Stellings exhaust resulting in a full 13db reduction. Part of the 13db is because the stellings is a true dry exhaust but with mufflers it becomes wet. That means we really gained just over 10db which is what we claim for that muffler. See 'Clamp-Ons' page for the new specs.

   Our 9075-PR mufflers (in-tubes) were put to the test in May 2007 by Maveric Marine of Van Nuys California. Eric reported that he ran these mufflers on a dynomometer using the Mercury 496 HO engine and no power loss was experienced. That's just right, this technology can increase power and that can be hard on valves. A big thank you to Eric at Maveric Marine for running the test.

   Lane of Big Guns Marine tried our 9062-PR mufflers (HP500s) on his race boat outfitted with a Mercury HP-500 engine this spring. Lane reported that his boat didn't lose any top end, in fact he thinks it gained 1 mph (GPS). He also commented that the muffler really quieted the motor down. Thanks Lane for the test and report.

   Chris in Martinez California purchased a set of 9062-PRs for his 454 at 400hp. He plans to do more engine work over the winter to bring it to 525 hp. Chris wrote, "Ran the boat for 3 days with new mufflers. Very happy!!! The sound is much more pleasant to deal with but still throaty enough to let people know there is an engine in there. If there was any loss in horsepower it's so small it's not noticeable. All and all I'm very happy! Thanks!!!" Hey Chris, Thank You for the feed-back.

   Danny of southern California purchased a pair of 9047-PRs for his 496 HO engine. He shows no top end loss on his GPS and says his boat now planes and climbs speed faster than with an open exhaust. Danny chided me for not telling him it might plane faster, he said I undersold the product. He also loves the sound saying you can now talk in a normal voice. 'They sound great, they took out the annoying reverberation but the engine still has a clean throaty sound.' His boat sound tested at 83 dba 10 feet back at dock level (86 required). He bought clamp-ons so he could take them off to regain performance and sound when he wanted but he said there is no need since the mufflers out performed an open system under all conditions. He has tested them both at altitude and on a 130 degree day. He told me, 'Dollar for dollar, these mufflers are the best investment I have ever made in my boat.' Thanks Danny for getting back to me. Oh yeah, Danny said that anyone with questions can e-mail him at

   Power Unlimited Custom Marine Inc. (now Harris Performance) purchased two sets of 9049-PRs for their 35 ft Baja with dual custom 700 hp engines. Jeff says they are very happy with both quieting and performance of these units. He reported that the top end actually gained 1 mph over an open exhaust. He says that is about 15 hp per engine. Then he said the test run had 2 extra people and 50 to 100 more gallons of fuel compared to the open system run. Thanks Jeff for the information.

   Gary of Kuna Idaho purchased a set of 9075-PRs for his 325hp jetboat with which he runs the rivers. He wrote that he was "really impressed". "Your mufflers didn't reduce my RPM at all and the sound is perfect and the installation is a breeze". Thanks Gary.

   Mercury Racing has approved APLs standard clamp-on silencers for use on the EU662SCI, HP600SCI and HP525EFI engines. 1075 clamp-ons are approved for use on all engines up through the HP1075SCI. Our 9060-PR transom mount silencers are approved for the HP525EFI, HP600SCI, EU662SCI and HP700SCI engines.

In-Tube Muffler
In-tube Silencer
In-Tube Based Transom Mount Muffler
In-tube Based Transom Mount Silencer
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38257 Airport Pkwy, Unit 2, Willoughby, OH 44094
Local: 440 602-9932   Toll Free: 866 602-9932
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