This is what I call the Ocean meditation, as delivered in Dan Siegel's excellent book, Mindsight. He kindly offers these for our use. JHM reads.

The duration here is 20 minutes. I recommend that you set a timer for yourself (most cell phones have good timers), and start the timer when you start the playback. This way, you can set the time for 10 minutes, 15 minutes, whatever fits your available time. There is no prompt at the end of the recording, so it will stop with no sound and you can stay in your state of concentrated awareness.