Each dismal news story about a drowning off Hawaii’s increasingly busy beach parks signals the need for change in how lifeguards are deployed.

On Oahu’s 29 city beach parks, where the population pressures are most intense, the need for increased staffing is indisputable.

However, proponents for extended-hours coverage, a proposal under consideration by the City Council, have not yet made the persuasive case that theirs is the most effective or efficient means of accomplishing the public-safety goal.

State Health Department records rank drowning No. 5 among the causes of deaths in Hawaii over the past two decades, with nearly half of the victims residents of the state. The toll was 273 drowning victims on Oahu between 2005 and 2014.

In response, Councilwoman Kymberly Pine has introduced Resolution 16-43, which urges the administration to extend the hours for the city’s roughly 140 lifeguards’ coverage, now largely limited to 9 a.m.-5:30 p.m.

It also calls for negotiations enabling the plan to be conducted with the lifeguards’ union, the Hawaii Government Employees Association.

The measure doesn’t specify exactly how this would play out, but among the overwhelmingly supportive testimony for the resolution are comments suggesting a four-day, 10-hour workweek. Proponents for that plan say that schedule would allow guards to recuperate and may decrease sick leave.

Ian Santee, deputy director of the city Emergency Services Department, said his office supports the intent of the resolution. However he projected that the city would need to hire at least 40 to 50 more lifeguards to cover shifts from sunrise to sunset. The salaries alone would cost about $3.5 million.

That’s a lot of money, and before the city commits to it, more study is needed. The wording of the resolution, which seems headed for adoption next week, should be tweaked to allow for that study and alternative approaches to be considered.

Officials should examine, for instance, whether public safety may be better served staffing up where the crowds are heaviest and when conditions are most hazardous, as opposed to stretching to meet all daylight hours. Part-time hires should be considered as an alternative.

“We need to start a discussion of how we can expand lifeguard hours,” Pine said last week.

No argument there. However that discussion should widen to bring out a full range of solutions.

Santee asserted that public safety is the city’s No. 1 purpose but rightly emphasized that there are other emergency-service needs that must be covered within budgetary constraints.

The idea he raised — of phasing in expanded hours in key areas — also makes sense.

Everyone agrees on the goal — safer ocean recreation for tourists and local residents alike. As written now, however, the measure pushes the city to lock in expanded hours for full-time staff islandwide.

A more strategic staffing plan, tailored to meet varying conditions throughout the calendar year, could achieve the stated goal at less cost to the taxpayers.