When all 5 of the Nauticon naval assault team combine, they form the immense super robot SEAQUAKE! Graaaahhh!!
I'm sure he has powers and stuff. He's got that big trident, and I think he's supposed to be able to generate a huge energy net. Really though, he's the least developed of the Nauticons. Most combiners are like that I guess. Big. Mean. Not much else going on. :)