Deep under the Red Sea, a passing Israeli warship could barely be heard as Yamit Avital held her breath and dived, her mind briefly cleared of the trauma of the 7 October Hamas attacks.

"There's a kind of tranquility to the sea, in the deep," Avital said after she emerged from 20 meters (66 feet) under the aquamarine waters of the Gulf of Aqaba, also known in Israel as the Gulf of Eilat.

"It's like you don't hear anything, you only hear the music of the sea."

She and her husband Benny are among the survivors from Nir Oz, one of the hardest hit kibbutzim in Hamas's devastating attacks that left at least 1,140 people dead in southern Israel, according to an AFP tally based on the latest Israeli figures.

Israel has vowed to destroy Hamas and launched a punishing offensive that has reduced vast areas of Gaza to a ruined wasteland and killed at least 21,978 people, mostly women and children, according to the Hamas-run territory's health ministry.

In the aftermath of the 7 October attacks, the Avitals and their three children were evacuated to Eilat, where they found themselves across the street from the coastal resort's Coral Beach Nature Reserve and its dive clubs.

Israel's diving federation, diving clubs in Eilat and dozens of volunteers have mobilised to offer evacuated Israelis courses in scuba diving and free diving — where divers plunge deep underwater on a single breath.

Yuval Goren, manager of the Aquasport dive club, said they were "desperate to give whatever we can" to help the evacuees.

Many participants said they found it a meditative exercise that assuaged their trauma.

'You gave back my smile'

Studies have suggested that therapy through scuba and other diving methods can be beneficial for treating trauma.

The novel underwater setting, physical activity, breathing exercises and body control, and exposure to and overcoming fear, can all serve to mitigate emotional pain, experts say.