Tropic Star Lodge in Piñas Bay, Bahamas, has re-powered its fleet of 13 Bertram 31 sportfishing boats with twin Volvo Penta four-cylinder diesels.

The 1970s vintage boats are now powered by D4 series inboard engines with ZF transmissions.

“We are very pleased with the result of our decision,” Ursula Marais, operations director and CEO of Tropic Star, said in a statement. “Volvo Penta demonstrated a great deal of flexibility and a commendable commitment to customer service in meeting our requests.”

The first installation was completed last year and two more will be completed in 2018. The remaining repowers will be finished on a phased schedule to ensure that there is minimal disruption to fishing. The first boat has more than 1,600 hours on the new engine and fuel usage is averaging 39 gallons per 11 hours, which Volvo Penta says is a 45 percent savings in fuel.

“This successful fleet repower project for Tropic Star, in one of the least accessible locations in the Americas, is a great testimony to the reliability and efficiency of our D4 engine platform, along with the creativity of our application engineering team and our dedicated service dealer in Panama,” Dave Brown, director of marine commercial of Volvo Penta of the Americas, said in the statement.

All maintenance will be performed at Tropic Star’s on-site yard, where the usage schedule is also managed. The boats spend most of their time trolling at slow speeds up to 12 to 13 hours per day. Volvo said the D4 is a good fit because of the Bertram 31’scompact engine compartment and because Tropic Star owners want to meet EPA Tier 3 emission levels.