noun
sea whistle; diver's whistle
A traditional whistling sound made by ama (海女) divers when they surface and exhale, used as a signal upon returning to shore. The term is culturally specific and may require explanation.
See also: 海女
海女が磯笛を吹きながら浜に戻ってきた。
The ama diver returned to the beach while making the sea whistle.
磯笛は、海女の伝統的な合図の一つだ。
The sea whistle is one of the traditional signals of ama divers.