Portland plumber Bob McPherson is a regular on local waters and said a weekend competition run by website operator Fishnet was well attended.

Teams representing Victoria and New South Wales battled it out for the biggest and best catch, with one keen competitor landing a 54-kilogram tuna.

"Victoria I think won it pretty well hands down," Mr McPherson said. "I think there was about 14 to 15 boats and there's probably 30 to 40 people in all those boats."

Mako and gummy shark, yellowtail kingfish, flathead and snapper have all been caught in good numbers, while albacore weighing more than 20 kilograms have proved consistent.

"This whole area's just starting to come alive," Mr McPherson said, adding that charter boats were busy meeting client demand.

A pod of seven blue whales has recently been spotted about five kilometres off the Cape Nelson lighthouse and has been joined by large numbers of dolphins and seals.

The tuna season usually finishes at the end of June, though enthusiasts are likely to try their luck into July.

"They're good eating - the tuna we catch here are exactly the same as the ones they have at Port Lincoln that are sold to the Japanese for big money," Mr McPherson said.