PORTLAND – Island residents who use golf carts to get around are being told they must register and insure their carts by the end of July.

City officials have begun enforcing a long-overlooked 1988 state law that requires the carts to be registered and insured as island-use-only vehicles.

Such vehicles, including cars and trucks, must display a special registration sticker but don’t need license plates or yearly state inspections to prove they are roadworthy. Owners must show proof of insurance to obtain a sticker.

Enforcement of the law comes as Great Diamond Island wrestles with a recent proliferation of golf carts, in part because they have proved to be ideal island transportation.

The city’s action also follows last month’s passage of a new state law that allows motorists to drive similar low-speed electric vehicles on streets with speed limits of 35 mph or less. In passing the new law, state officials learned that Portland wasn’t registering island golf carts and pushed the city to begin enforcing the law.

Some island residents initially balked at the idea of registering and insuring their golf carts. They said they couldn’t find companies that would insure golf carts and feared that the policies would cost too much.

Now many islanders are ready to comply with the law, especially since Thomas Fortier, Portland’s island liaison, tracked down at least three local companies that offer golf cart insurance policies for as little as $50 per year.

“It’s a matter of safety, for the drivers as well as the pedestrians,” said Judy Savastano, who lives on Great Diamond Island, which has about 120 golf carts. “The law is the law, whether you live in Portland or on an island. You don’t just move to an island and forget the rules.”

It will cost $16 to register an island golf cart at the treasurer’s office in City Hall. That pays for a $3 sticker, a $4 state registration fee, a $4 abandoned vehicle fee and a $5 flat fee for excise tax.

“We’re trying to transition into this policy slowly,” Fortier said. “Island constables will be working with each community to bring residents into compliance.”

Still, some residents have reservations that are typical of independent island life.

“It’s probably helpful, all in all, because they are motor vehicles, but I don’t see it as a major addition to our public health and safety,” said William Hall, who lives on Peaks Island, which has about 100 golf carts, in addition to hundreds of cars and trucks.