The National Park Service is seeking public comments on a formal plan for commercial air tours that fly over the Point Reyes National Seashore and other Bay Area parks. The new air tour management plan, which the parks were required to draft in collaboration with the Federal Aviation Administration, imposes specific limits on altitudes, flight times and types of aircraft.

Just one private company operates air tours over the seashore: Seaplane Adventures, a 75-year-old business based in Mill Valley. The company runs under an interim operating authority with the park service that allows 5,090 commercial air tours per year over the seashore. The agreement places no restrictions on the routes those tours take, the time of day or the altitude. The new plan would limit tours over the seashore to 143 annually, the current average.

“What’s being proposed in the draft is really formalizing what’s actually been happening,” said Alison Forrestel, chief of natural resource management at Golden Gate National Recreation Area, which is included in the plan.

Yet Seaplane Adventures owner Aaron Singer said the new altitude regulations would be next to impossible for his pilots to meet. “These impractical rules of changing altitude by 1,000 feet over the duration of less than half a mile are just not practicable,” he told the Light. “It would be potentially dangerous.”

The company’s Norcal Coastal Tour, which costs $319 per person and takes off from Richardson Bay, meanders over Mill Valley and Mount Tamalpais before entering park airspace over the Bolinas Ridge and crossing over the Phillip Burton Wilderness Area. The plan would require the company’s seaplanes to fly a minimum of 1,500 feet above ground level when passing over parkland, and 2,000 feet above the wilderness area, to protect habitat and reduce noise for visitors. Currently, the seaplanes fly as low as 800 feet. 

The tour then travels across Drakes Bay and crosses over the B Ranch before looping back around the Point Reyes Lighthouse. Under the proposed rules, the planes would have to avoid ranch core areas by 2,000 feet laterally to minimize disturbance. 

“Over the years, the park has received phone calls from ranchers who have observed flights over their dairies and are concerned the noise is disturbing dairy cows,” Brannon Ketcham, a management analyst at the seashore, said.

The Norcal Coastal Tour hugs the coastline as it returns to Richardson Bay, passing over Double Point and Duxbury Reef, where the plan would require it to remain a half-mile to three-quarter-mile offshore and above 1,500 feet to prevent any disturbance to sensitive marine mammals. One of the primary goals is to protect wildlife, Mr. Ketcham said. 

“As they’re proposed, with the minimum flight altitudes, we anticipate [the tours] would have no effect on those species,” Mr. Ketcham said. 

But Mr. Singer said his planes already fly high enough to prevent impacts on wildlife, and that flying too high is incompatible with his business. “The higher you are, the less people can see,” Mr. Singer said. “Fifteen hundred feet is a good compromise altitude. I’d rather fly lower.”

Additionally, he said, the proposed management plan would force seaplane pilots to rapidly change altitude. His de Havilland Beaver and Piper Super Cub planes can climb and descend at just 200 to 300 feet per minute, meaning they could stall under those conditions. 

At a public meeting last week, F.A.A. policy advisor Eric Elmore said his agency’s Flight Standards District Office in Oakland had reviewed the proposal for safety and found it satisfactory.

All the new restrictions will be monitored through semiannual reports the company must begin submitting to the park service, including readouts from onboard flight monitoring equipment.

Seaplane Adventures has avoided increased restrictions in the past. In 2017, the Marin County Planning Commission decided to reject proposed limits to Mr. Singer’s use permit that stemmed from noise complaints by residents of Mill Valley and Strawberry. Commissioners initially recommended limiting the number of daily flights from Richardson Bay, but stopped short of imposing any new restrictions, concluding that F.A.A. regulations trumped the commission’s jurisdiction. 

Parks across America have air tour management plans, which do not apply to general aviation, commercial airlines or drones. Generally, the plans do not allow parks to collect fees from these commercial air tour operators, with the exception of Grand Canyon National Park and several parks in Hawaii. The management plan would have no effect on parks’ budgets, officials said. 

Comments on the draft can be submitted online at until Nov. 15.