A shark was spotted lurking in knee-deep water in the Bay of Plenty today.

Onlookers watched from the shoreline of Waihi beach as the sizeable shark cavorted in the shallow waters, in between small waves.

The sighting came after two young fishermen in a kayak hauled in a large bronze whaler, estimated to weigh as much as 150kg, at Waihi Beach on New Year's Eve.

The kayakers, thought to be in their early 20s, spent about an hour bringing in the shark, before they let it go.