I'd say its a kingy mate, they frequent the wharf this time of the year till about March.
The same thing happened to me as well, I was fiddling with my bag when a lady started yelling , I turned around and to my surprise I saw my spinfisher 950 bobbing up and down, smacking it self against the railing, I quickly ran and caught my outfit, however I managed to lose yet another fish to the pylons in about what was 5 seconds. Only one of the guides were damaged, lucky I didn't lose the whole thing overboard, although I probably would have went in after it, it was brand new at the time too.