New Hampshire allows wake surfing closer to the shore than even the boating and water sports industries recommend. For that to change, lawmakers will have to reach an agreement on just how far to push surfers offshore.

Wake surfing — a water sport where surfers ride the wake created by a motorboat — can have unintended environmental consequences. It churns up phosphorus-rich lake sediment, spurring the growth of algae and harmful bacteria, and its waves can cause shoreline erosion and pose safety risks to others in the water.

Senate Bill 431 seeks to address those concerns by restricting wake surfing to water bodies of at least 50 acres. It would also push wake surfers farther offshore, but disagreements over the distance — 200 or 300 feet — may kill the bill entirely, despite bipartisan support.

Sen. Tim Lang, a Sanbornton Republican and sponsor of the bill, said he felt the 200-foot distance passed by the Senate was a “reasonable compromise” that would prevent shoreline erosion by allowing waves to dissipate instead of crashing onto land. This is the standard backed by the boating and water sports industries, but not everyone agrees that it’s enough to protect the shore.

Rep. Jessica LaMontagne, a Dover Democrat, worked in the House to amend the bill to a 300-foot restriction, which she said is more protective and easier to visualize. She said she would rather the bill die altogether than pass it with just 200 feet of shoreline protection.

The large, ocean-like waves generated by wake boats can take between 400 and 1,023 feet to dissipate to levels of typical boats moving at cruising speed, according to a Michigan Department of Natural Resources review of research on how wake boats impact aquatic habitats. That review recommended wake surfing and boarding be restricted to at least 500 feet offshore and to water at least 15 feet deep.

Currently, in New Hampshire, wake surfers must be at least 150 feet away from the shore. That’s closer than the 200 feet supported by the Water Sports Industry Association and the National Marine Manufacturers Association, a trade group representing boat manufacturers.

Other New England states have gone further than the industry standards. Vermont, for instance, adopted a new rule in April that requires wake surfers to be 500 feet offshore and in water at least 20 feet deep. Maine recently approved restrictions for 300 feet offshore and 15 feet in water depth.

Efforts to address wake surfing concerns in New Hampshire have long faced legislative challenges. Another bill this session, House Bill 1301, would have allowed the Department of Safety to ban or restrict wake surfing on a public body of water through a petition and hearing process. The bill died in the House.

The 100-foot difference that separates the House and Senate versions of SB 431 would affect only five water bodies, according to data from the New Hampshire Department of Environmental Services. If a 200-foot and 50-acre restriction is put in place, 290 water bodies in the state can still be used for wake surfing. In a 300-foot and 50-acre scenario, 285 are left up for use.

“The additional setback to 300 feet does not prohibit wake surfing on any additional lakes, but it does address vulnerable areas on rivers,” said Andrea LaMoreaux of NH LAKES, a nonprofit focused on the health of the state’s lakes that supports the 300-foot restriction.