With the Fourth coming on Friday, booming fireworks are being heard with increasing frequency around the island.

Of course all those booms are illegal, except those that originate in a 12-hour window on the big day itself.

Legal fireworks – including sparklers, spinners and fountains (for a complete list go to www.wsp.wa.gov) – can only legally be discharged on the island between 11 a.m. and 11 p.m. on Friday. Other devices, such as firecrackers, bottle rockets and missiles are legal on tribal lands, but illegal to possess or discharge at any time on the island.

M-80s and other explosive devices, including those created through the alteration of legal fireworks, are illegal throughout the state.

Discharge times vary by city, so those looking to celebrate elsewhere should check with local sources.

Violators on Bainbridge will be subject to fines that vary depending on the severity of the crime, Deputy Police Chief Mark Duncan said.

The island has already experienced some fireworks-related crimes this summer. Several juveniles were arrested last week in connection with the detonation of “sparkler bombs” in portable toilets around the island.

Duncan said it’s important to distinguish between using explosives and other more benign fireworks violations.

Penalties for those caught making or using sparkler bombs include possible jail time, he said.

Islander Vicki Kirkman said she’s usually on edge this time of year. Four years ago on the Fourth she was trampled by two of her own horses as she tried to calm them amid the noise of a neighbor’s fireworks display.

Kirkman suffered a broken clavicle and an injured knee in the incident and has since pushed the city for a ban on fireworks.

Officials are considering a ban or other possible changes to the city’s fireworks ordinance, though no specific proposal is on the table; a ban can’t take effect until 12 months after its passage.

Nearly 54 percent of island residents said in a 2004 advisory vote that they would oppose an outright ban on fireworks.

Still, Kirkman said, it’s worth considering.

“Fireworks can be a dangerous thing,” she said.