Shaw was checking a mate's boat on Tuesday when Charlie started to bark.
''Charlie doesn't bark without a good reason. He started nutting off at this seal and the seal half leapt out of the water.''
With his front flippers and head on the walkway, Sammy began barking back.
''Charlie got such a fright that he ran away and fell in.''
The seal responded by slipping back into the harbour and Shaw hurriedly pulled Charlie out of the water.
''I had him on a lead and hauled him straight out. I don't know who got the biggest fright, the seal or Charlie - probably Charlie,'' Shaw said.
Marina manager Tony Arnold said Wednesday's episode with the dead fish showed how Sammy was a real show off.
''He rolls over and eyeballs you - he is not bothered by humans. It looks like he is smiling, he is having so much fun.''
Arnold said Sammy was throwing the fish around all over the place, with a seagull hovering above trying to grab it.
There were a lot of sprat and herrings in the harbour, with fish and birds after them and Sammy in the middle of it all, he said.
The seal was nowhere to be seen yesterday. Since his arrival, he had spent a lot of the day napping on rocks under the deck of Phil's Place restaurant.
Phil's Place duty manager Andy Hislop said everyone was leaning over the deck taking photos of Sammy on Wednesday. ''He was having a good frolic in the morning and then went to sleep under the deck.''
Hislop said the seal was pretty cute and playful, almost like he was showing off.
Department of Conservation community ranger Tracy Mezger said this time of the year was the haul-out season for seals, when weaned pups were leaving their parents and dispersing.
''People should not bother them because they are chilling out and resting. Winter time was a time for rest and sleep - a lot more than other times of the year.''
They came ashore, sometimes in what seemed like unusual places, and she warned people not to approach them because they had a nasty bite and carried diseases.
DOC tips for New Zealand fur seals
- They will defend their territory aggressively.
- Can bite with more strength than a large dog.
- Do not get closer than 20m.
- Do not get between the seal and its access to water.