Deputies have voted against a bid to increase fees by just 10% in a re-run of December 2023's debate.
A requete brought by deputy David de Lisle failed to get the support needed to overturn above-inflation rises in private mooring fees which will take effect in April 2024.
Deputies voted 20-18 against, with the two Alderney politicians not voting.
Setting out his argument, deputy de Lisle said the fees were damaging boating and Guernsey's wider marine industry, that services vessels:
"The leisure boat industry is shocked and reeling by mooring fee increases of 20-31% for 2024.
This is nothing short of a preposterous attack on boat owners. The leisure boat industry is being put at severe risk. Mooring fees, have traditionally been at a level that a person of average means could afford."
Deputy Peter Roffey, whose STSB committee has responsibility for the harbours and brought in the above-inflation increases to help stem losses, argued that the motion had no place back in front of deputies:
"This requete has created a carbon copy of the debate we one that we had at length just a few months ago. And I do wonder about the good governance of this Assembly, if every time a vote is narrowly lost, or passed for that matter, we re debate the issue just to see if there'll be a different outcome."
Deputy Roffey said the board looked at where efficiencies could be made and which fees and charges could be increased:
"What rapidly became apparent was that our private mooring fees were way below commercial levels. We felt it was a problem when we are asking Mrs Le Sauvage to subsidise the ports out of her taxes."
However, the Assembly agreed that there should be further consultation before any more increases are brought in.