The pod swam alongside the bottom of their boat for five to 10 minutes, Simon said.
“And the further we cruised out, the more that showed up and they were just coming towards us.”
“It was pretty cool.”
Simon posted a video of the encounter on Facebook.
New Zealand Whale and Dolphin trustee and professor emeritus at the University of Otago Liz Slooten said they were common dolphins (Delphinus delphis) based on the video.
“They have this kind of hourglass pattern on the side of them where the front part can look quite yellow, fawn or yellow coloured.
“And the rear part of the hourglass is usually more grey.”
Common dolphins are located almost worldwide.
They tend to live in deeper water offshore and can be found in large schools as big as thousands, “which is a really impressive thing to see”.
They have a more pointed, “shark-like” dorsal fin as opposed to the rounded dorsal fins found on New Zealand’s endangered Māui and Hector’s dolphins.
The dolphins were likely curious about the boat, Slooten said.
“They are just very playful.”
“It’s a little bit like a dog chasing a stick or a ball.”
Common dolphins are a faster-swimming species of dolphins, easily keeping up with a boat going 10 knots.
“They’re just a beautiful animal.”
Simon said he had been fishing in Whanganui since he was young and this was not the first time he had seen dolphins in the area.
“Always a fun surprise.
“It was the first time I’d seen that many.”
The three friends enjoyed their unexpected visitors and caught a few fish.
“Perfect conditions to be out on the water,” Simon said.
“I wouldn’t be surprised if the dolphins caught more than us though.”
Erin Smith is a multimedia journalist based in Whanganui.