Captain Carl Sputh of motoryacht Starfire and his father Captain Ted Sputh began testing exhaust-treatment system clean-exhaust in 2012. After two years of testing, The Crew Report catches up with the father-son team about the system.

“The problem with most exhaust systems out there now is that you can’t adjust them and make the product work more or less hard as the generator gets older,” explains Captain Carl Sputh, who used this conversation point as the starting point of clean-exhaust’s development with Starfire’s then-chief engineer Andrew Connelly. “So we started talking about the way they’re doing it now – they’re trying to burn off all the non-burned fuel and carbon with scrubbers. We thought we should be able to destroy it some other way and not burn it off. We thought, maybe they’re doing it the wrong way; maybe there’s a chemical way to do it.”

"The best experiment was on Mia Elise. After three days, the hull was pristine ... We then turned off the system and 18 hours later the water was full of floating black sludge and the top sides were dripping with black soot."

This is when the two came up with the idea of injecting the emulsifier into water drop mufflers, which was tested on Starfire with success. “The results were incredible,” says Captain Carl Sputh. “As the generators got older, they were putting out more oil, carbon and un-burned fuel and with clean-exhaust we were able to adjust the system and destroy the particulate.”

clean-exhaust in use

Captain Ted Sputh joined the clean-exhaust team and began setting up testing on a number of superyachts – six of which still use the system. “The best experiment was on Mia Elise. We cleaned the hull and put a blue tape ‘X’ above the exhaust exit. After three days, the hull was pristine around the ‘X’. We then turned off the system and 18 hours later the water was full of floating black sludge and the top sides were dripping with black soot. It was very dramatic to go from zero to very nasty particulate,” explains Captain Ted Sputh.

The father-son team points out that the clean-exhaust system, which costs around $15,000 (a figure both captains purport to be significantly less than alternative market solutions) must be running all the time. “If the vessel runs out of emulsifier [in this case, ecoBrew] and doesn’t run the system for two months and then decides to run it again, all of a sudden engineers and crew start complaining that it’s not working,” reveals Captain Carl Sputh. “If you continuously run clean-exhaust it works all the time – it isn’t a system you can turn off for half of a Med season or an Atlantic crossing.”

Father and son captains: Ted Sputh (left) and Carl Sputh

Another potential pitfall is one not associated directly with the system. Captain Ted Sputh points out that communication between the deck department and the engineering department needs to be good to make the most of this type of system. “It’s really the deck crew who are cleaning the hull. They are the people who are happy or not happy with how it’s all working. We have two adjustments – a stroke and a pulse. If it needs to be turned up it must be communicated to the engineer and he has to facilitate the change.”

Those who have used the product as instructed have seen exciting results, all of which can be found on the clean-exhaust website. I do put the question to Captain Carl Sputh about whether his position as a current captain is helping sell the product. But, for him, the product sells itself. “I think clean-exhaust is great, we use it on Starfire, but I don’t want to push anything on any friends – I’m not that kind of person. When the word gets out that it’s working on the other boats people will listen. The system works – I wouldn’t be talking with you if it didn’t.”

If you like reading our Editors' premium quality journalism on, you'll love their amazing and insightful opinions and comments in The Superyacht Report. If you’ve never read it, click here to request a sample copy - it's 'A Report Worth Reading'. If you know how good it is, click here to subscribe - it's 'A Report Worth Paying For'.