Yes, I know out of universe it’s just to sell toys, but I cannot for the life of me think of a reason why they’d be necessary.
Most of the climate variants of stormtrooper armor make sense. Snowtroopers? Provide protection against extreme cold. Magmatrooper? Provides protection against extreme heat. But shoretroopers? I just don’t get what their armor could add or improve to make their development worthwhile.