Sunbathers who pick the wrong sunscreen may suffer from skin damage even if they apply enough initially and re-apply it after a dip in the pool. The problem is that not all sunscreens deliver the sun protection factor or SPF that they promise, according to Consumer Reports. Those seeking protection from the sun need to make sure their sunscreen delivers the SPF they think they’re buying.

Consumer Reports found that 43 percent of the products they tested this year did not deliver the SPF promised on their labels. Consumer Reports tested more than 60 lotions, sprays and sticks that claim a 30 SPF rating or higher — the minimum SPF recommended by the American Academy of Dermatology —and found that 28 of those fell short.

Three of those tested by Consumer Reports came up with a dismal showing of an SPF less than 15. That’s the kind of failure that can expose users to sunburn, wrinkles and skin cancer.

It is not just this year’s products that don’t offer enough protection. Consumer Reports has tested sunscreens for four years—a total of 104— and concluded that almost half failed to come up to their SPF claims following immersion in water. They found results from “natural” sunscreens containing only mineral products to be particularly troubling. The mineral-only sunscreens containing only titanium dioxide or zinc oxide performed much worse than the chemical sunscreens, said Consumer Reports.

They did find a few natural sunscreens that performed well:
• Cotz Plus SPF 58 ($20)
• California Baby Super Sensitive SPF 30+ ($19.99)
• Ocean Potion Protect & Nourish SPF 30 (oxybenzone-free, but is a chemical-based sunscreen) ($7.99)

These were the lotions rated best by Consumer Reports:
• La Roche-Posay Anthelios 60 Melt-In Sunscreen Milk ($36)
• Pure Sun Defense SPF 50 ($6.30)
• Coppertone Water Babies SPF 50 ($10.50)
• Equate Sport Continuous Spray SPF 50 ($7.85)
• No-Ad Sport SPF 50 ($10)

The top five performers among sprays:
• Trader Joe’s Spray SPF 50+ ($6)
• Banana Boat SunComfort Continuous Spray SPF 50+ ($10)
• Neutrogena Beach Defense Water + Sun Protection SPF 70 ($10.50)
• Caribbean Breeze Continuous Tropical Mist SPF 70 ($16.60)
• Equate Sport Continuous Spray SPF 30 ($4.98)

But if you can’t find a sunscreen rated highly by Consumer Reports, pick a chemical sunscreen with an SPF of 40 or higher. That choice puts you closer to winding up at least an SPF 30, the minimum level many dermatologists recommend.

Don’t rely solely on sunscreen products for protection from the sun’s UVB rays. Pay attention to the time of day and the hours you spend in the sun. Remember to avoid too much exposure by wearing a hat and covering up.

For the full low down from Consumer Reports, read their article Get The Best Sun Protection. A list of all 69 ratings for 2016 is available if you subscribe to Consumer Reports.