PORTLAND – While 50 degrees can sometimes be considered warm for Maine, 50 degrees in water is deadly cold.

Fifty-degree water can render a 160-pound person unconscious in 15 minutes to an hour, and death from hypothermia is likely in as little as two hours, according to Coast Guard Lt. Paul Wolf.

“Although the weather is nice and the ocean is very inviting, it’s also very unforgiving, especially at this time of year,” he said.

Now that the Memorial Day weekend is over, more recreational boaters are expected on the water, and the Coast Guard wants to remind them about safety.

Even strong swimmers need to wear life vests to keep them afloat should they pass out from hypothermia, Wolf said.

“Do like we do,” he said. “Any of our vessels that are under 65 feet long, we’ve got them on all the time. Just because you never know what may go wrong.”

His other tips include staying near the boat if you end up in the water.

“If the boat sinks or capsizes, as long as possible, stay with the boat. That’s what we’re looking for, that will help you conserve energy.”

And, he noted, “the boat’s easier to see than your head.”

Once in the water, drawing your knees to your chest and wrapping your hands around them will help lengthen the time a person can survive in cold water.

He also recommends having a good marine radio and flares.

“Having the ability to pick up that [microphone] and call for the Coast Guard is potentially going to make a life-and-death difference,” he said. “No matter where you are on any of the U.S. coasts, on the Great Lakes, on the Ohio, Missouri and Mississippi rivers, pick a spot anywhere on those and pick up something as small as a little hand-held radio, call the Coast Guard on Channel 16 any time, any day and you will be answered immediately.”

While wireless telephones are better than nothing, radios are still better, he said.

While some people may favor high-tech survival tools such as emergency beacons, old-fashioned equipment is still a must.