How do dolphins sleep?

Some years ago I read an article written by a marine biologist and he said that the had observed dolphins and it appeared to him that some dolphins were just laying on the sea bed in a shallow lagoon and about every 10 to 15 minutes the dolphin just came to the surface the sank again without any apparent other movement . He concluded that the dolphin was asleep and had some sort of body reaction that made it come to the surface to breath when necessary. Similar I suppose to us sleep walking. This is not proof that they sleep of course but it is some evidence

Dolphins allow 1/2 their brain to sleep at a time, by lying on the ocean floor and surfacing for air when needed.

Dolphins do sleep in shallow waters and come up for a air

every so often 1 1/2 to 2 hours ,,when motionless their heart beat slows down they don't need to pop up for air so often ..

Hi >

Dolphs, I love them, and have swum with them night & day in the Mid-East.

I am no zoologist, but they seem to "switch off" and just float around on the surface to slowly breath.

For about 4/5 hours per evening.

Then they have my Dolph squid breakfast, and chase the boat.

All is well.

Bob.

They sleep as said with one eye shut. But the real reason is that they are petrified of giant tiger prawns. And in all honesty, can you blame them when you order some Prawn Balls from the Chinese.. The size of them. No wonder also that the crabs walk sideways

They rest on the bottom for like an hour then they automatically wake up and get some air then go back down to rest.

They sleep on there bellies n float to the top of the water

only one half of the brain is under sleep.and it is for 8 hrs a day.they sleep along the surface....

One eye closed, half brain sleep..thought I saw that on Discovery/Nat Geo channels ...but not sure...