@Mn-guy Yes, other units can participate in the sea battle. Other than being a prelude to an amphibious assault, it is just like any other sea battle. The rules on page 15 mention only battleships and transports because they are the only units that can participate in the land battle.
As a side note, attacking air units must, of course, be assigned to either the sea or the land battle, as indicated by where they end their combat movement. They cannot participate in both, even if the amphibious assault is against an island.
