Running a Marine Generator: Does it Spook Fish?

Top captains weigh in on the question of whether running a marine generator spooks fish or not.

Marine generators are quiet, but fish can still hear them running.
Marine generators are quiet, but fish can still hear them running.
Some fish species seem repelled by the noise of a marine generator, while others are not, according to some top sport-fishing captains.Courtesy Westerbeke

My June 2012 Better Boating column led to an interesting question: Does running a marine generator spook fish? We asked charter captains for their opinions.

"I believe that open-water fish like mahi, marlin and sailfish don't seem to be bothered by generator noise," said Ray Rosher, captain of the 43-foot Miss Britt II out of Miami. "But shallow-water fish like bonefish, tarpon, permit and seatrout are more prone to move away from a boat with a motor or generator running." Rosher believes that shallow-water species initially spook away from the noise, but that they can also be acclimated to the sound of a genset.

In Southern California, Gary Adams, captain of the 65-foot Rail Time out of Huntington Harbor, is one of the best white seabass skippers, and he believes that stealth is important. "I think it helps to be as quiet as you can for seabass fishing," he said. "That's why sometimes the guys with smaller boats catch them in shallow and we don't. I think the noise makes them swim away."

Finally, a well-known skipper in Bermuda believes that generators have a positive effect on fishing, at least when trying to catch bait fish. "We have found that when fishing for live bait such as scads – aka speedos – they come to the boat better when we leave the generator or the main engine running," said Allen DeSilva, captain of the 56-foot Carolina Sportfisher, Mako. Ultimately, however, most of the skippers said that if in doubt, turn off the genset and main engines, particularly when fishing wrecks, reefs and other structure.