GULFPORT, Fla. — Gulfport city leaders are expected to vote Tuesday on whether to raise commercial rates at its municipal marina, a proposal city documents show could make it the most expensive municipal marina in Pinellas County.

City officials have said the new rates are intended to generate revenue and help offset the cost of “possible losses” tied to Amendment 3, which, if passed in November, could significantly reduce property tax revenue for cities and counties across Florida.

Commercial boaters who use the marina say they believe they are taking the brunt of the increase. Under the proposal, commercial boaters would pay higher slip rental rates plus an additional fee for each vessel.

If approved, the new rates would take effect in January and increase again in July.

Captain John Ross, owner of Beach Charters by the Bay, said he currently pays $655 a month for a wet slip at the marina. He said the proposed increase could add about $1,500 a month in just fees for his three boats.

“Right now, the new proposal is just astronomical what they’re trying to get out of us,” Ross said.

Ross said he has operated out of Gulfport’s municipal marina for five seasons, offering eco-tours, sandbar trips and other charters. He said the location provides convenient access to Boca Ciega Bay for both his business and customers, but the proposed rates could force him to consider moving.

“I was looking at expanding, getting some more boats to get more customers out on the water and experience Tampa Bay, and now I have to plan on, ‘OK, I might have to move,’” Ross said.

Gulfport’s mayor, city manager and marina director declined requests for interviews.

During a September council meeting, city officials acknowledged the proposed rates would be higher than rates in other cities, including Clearwater, St. Pete and Dunedin. They argued Gulfport offers amenities that help justify the cost and said other cities could also raise rates if Amendment 3 passes.

City officials also discussed maintenance concerns at the aging marina, including worms eating pilings. Marina director Denis Frain says they may only have “five to seven years,” if nothing is done.

But the ripple effects from this decision stretch far beyond the water, Ross said. He often recommends local restaurants to charter customers after trips.

Matthew Neumann, owner of Hookin’ Ain’t Easy, said he gets 300 customers a month referrals from charter captains. They bring valuable business to his restaurants and other nearby businesses.

“If we lose those captains that bring tourism here locally, it’s going to affect not only myself and this business, but all the surrounding places around here,” Neumann said.

City staff also noted during the September presentation that demand remains high for space at the marina, with as many as 150 people on the waiting list. That could make it easier for the city to fill slips if some commercial boaters leave.

For Ross, Tuesday’s vote could determine whether he stays in Gulfport or looks for another marina.

“They’re trying to recruit more money from us, but, in the end, if we all leave, they’re going to lose millions,” Ross said.

Gulfport officials will take up the vote at their meeting Tuesday night at 6 p.m. at City Hall.