yeah i have had a run in with a few of these monsters!!! one went over a meter and i had actually called it for a shark till it was right near the boat.... mine also circled the boat, ran and then collided head first into my anchor rope which stunned it long enough for me to cut him loose.
not exactly sure what species they are, but they are a ball of muscle, that for sure. good fun till you have to clean all the slime up!!
pete