Robbins was a boatman who was hired by George Trenchard to take the Third Doctor and Jo Grant to Fortress Island to see the Master. He was a member of the lifeboat crew who went to look for the survivors of sinked ships. Later, he confirmed to the Doctor that a number of ships had recently vanished without a trace. (TV: The Sea Devils)
Behind the scenes
In the novelisation, he is given the first name of Thomas.