Boaties are firing a shot across government bows over the multimillion dollar impact of the Regional Fuel Tax.

Marine industry leaders say it's "clearly unfair" recreational boaties must pay twice to fix problems on the roads - once when they fill their cars and again when they fill their boats.

Designed to fund congestion-busting projects, the Regional Fuel Tax (RFT) will net about $7m a year from some 220,000 boaties, the NZ Marine Industry Association predicted.

The majority own trailer boats, rather than more upmarket craft moored in marinas.

The association reached its forecast using "industry accepted figures". It said Aucklanders were already paying a huge chunk of the $102m collected nationally as excise duty and GST on fuel for boats.

Operators of commercial vessels can apply for refunds on the RFT but recreational users cannot.

Transport Minister Phil Twyford told the Herald that's being considered in a wider review of fuel levies.

The 11.5 cents a litre RFT was introduced by the Government and Auckland Council on July 1. Charged on petrol, diesel and biofuel, it's designed to raise $4.3 billion over 10 years for projects such as light rail to the airport and new roads.

The Marine Industry Association estimated the annual cost to boaties will range from about $58 for petrol-powered dinghies to $230 for moored launches and large rigid hull inflatables.

"Getting out on the water is a national pastime," said Busfield. "We believe it's not in the best interests of Kiwi families to make time spent in the family dinghy or weekends heading out to go fishing an unaffordable hobby."

The new tax could also have "harmful consequences" for businesses.

"While it's clearly unfair to tax a recreational group to pay for another sector's infrastructure, the effects will be felt far more widely than solely in boaters' wallets," said Busfield.

"The Auckland recreational boating industry contributes significantly to the national economy.

NZ Marine Industry Association executive director Peter Busfield says the Regional Fuel Tax is "clearly unfair" on recreational boaties. Photo / Doug Sherring

"Many of our member companies across the country build and service boats bound for Auckland; with a large number of them dealing with the smaller vessels that make recreational boating in New Zealand so accessible to people from all walks of life.

"We, as an industry, strongly feel this disincentive to boaters in Auckland will have harmful and wide-reaching consequences for our member companies."

Recreational fishing lobby group LegaSea agreed the tax could hit the number of everyday Kiwis who could afford to run boats.

"How many more barriers can we design to batter down participation? It will drive us back to the couch and the mall," spokesman Scott Macindoe said.

"It adds to the heavy, dreary sinking lid of indifference and hostility from government. Nothing comes back to recreational fishing."

The cost of a litre of regular petrol has reached $2.40 in some areas.

Auckland Action Against Poverty this week said the fuel tax was disproportionately affecting the poor, echoing concerns raised by the Independent Maori Statutory Board last month.

Busfield said the RFT would be easier to swallow if it meant extra money being returned for marine environmental projects, boating safety or extra marine facilities.

Under $9m a year was returned to the sector through boat safety education and related activity.

The Hauraki Gulf was the largest "park" in Auckland and the council was making little effort to improve access, he said.

Auckland Council said it had a rolling schedule to repair or renew boat ramps.
Such projects required specialist engineering work which was costly and funded from local budgets.

Legislation allowing the introduction of the fuel tax was fast-tracked after the formation of the Government late last year.

Busfield said concerns about the impact on boaties were raised with Auckland Council and the Government.

He believed the Government had been happy to turn a "blind eye".

Chris Galbraith, chairman of the Marina Operators Association, said some of its 45 members had made individual submissions to the minister.

The Ministry of Transport advised Twyford a refund system would be needed for non-road uses of fuel.

Like "personal marine craft", operators of aircraft, forestry and road-building vehicles are among those who are ineligible.

Transport Minister Phil Twyford says boaties may be able to apply for refunds on the Regional Fuel Tax, depending on a review being carried out by his ministry. Photo / Mark Mitchell

Twyford said the Cabinet based the rules on existing regulations around refunds for excise duty and GST on fuel.

The "outdated" regulations had been a problem for successive governments and he had ordered a full review.

Boaties might be able to claim backdated refunds, depending on the outcome.

"The regulations need to change to better reflect our current transport environment."

The Ministry of Transport is on track to complete the review by the end of next June.

"The ministry is keen to see fairness for off-road users of fuel," said senior official Marian Wilberg. "We also need to make sure we can administer an effective refund system.

"Pleasure craft are a good example of the complexities the review will address. These have not been entitled to a refund for fuel excise duty since at least 1966. This is because the fuel excise duty paid by boaties provides vital funds to boat safety activities, including search and rescue."

Auckland Mayor Phil Goff said he had always believed all non-road use of fuel should be eligible for a rebate.

"I welcome the Minister of Transport's review of the rebate scheme and I look forward to progress being made on this issue."

The Marine Industry Association represents around 470 companies, including boatbuilders, equipment manufacturers and marinas.

It organises the Auckland On Water Boat Show, on this weekend at the Viaduct Events Centre.