This is the ‘Changing Tides Blanket’ which was a Crochet Along hosted by Eleonora Tully from Coastal Crochet.
It ran for 16 weeks from 12th April, 2019. The pattern remains available over on the Coastal Crochet Blog or as a pattern download here on Ravelry.
https://coastalcrochet.com/2019/04/12/changing-tides-week-1/

Eleonora used the changing tides of the sea as her inspiration throughout the design process… from turning the blanket on each round just like the tides turn, to the different stitch combinations, textures and the colour choices too.