State regulators and neighbors also warn of other problems: If the lighthouse is built, they say, it could set a bad precedent, block residents' views and change the peninsula's character.
"We just think it's overkill," said Elliott Bonn, who lives across Balboa Boulevard from the proposed community sailing center and park between 15th and 18th streets.
The amendment would be for the Marina Park project specifically, a point that city officials hope will allay any concerns about setting precedent.
The lighthouse would help visiting boaters and beachgoers find public amenities, according to a city staff report. But in that same report, planners call the lighthouse "nonfunctioning," referring, presumably, to its low-wattage lamps.
They also say that the "tower is anticipated to become an iconic feature for the facility, which reflects the city's history and culture."
Orange County has no working lighthouses, according to a national directory maintained by the University of North Carolina. Oceanside has a faux lighthouse.
Flanked by buildings about half its height, the tower would taper from 18 feet wide at its base to 8 feet at its top, the project's environmental impact report says.
Residents across Balboa Boulevard look toward the bay and the bluffs above. Even without the lighthouse, the sailing center would likely block or obstruct some of views.
While the city is not obligated to preserve private views, it has to follow state regulations that protect public views. From public vantage points, the lighthouse "is not bulky, obtrusive or otherwise objectionable in nature," the staff report reads.
"That's a crock," Bonn said. "If it's not, then how is anybody going to see it?"
Fellow peninsula resident Louise Fundenberg agreed.
"They ought to keep everything low," she said. "It makes vision better for everybody."
Fundenberg also worries about other property owners who might want to build a tower on the harbor.
City planners and a citizens committee spent years designing the $6.8-million Marina Park project, and debated over the building's height. Because the lighthouse was considered an "architectural element," officials thought it was exempt from zoning regulations.
"We've gone through an extensive public outreach," said Councilman Mike Henn, who represents the peninsula. "The entire community was involved in that."