St Ives lifeboat crews were called out at the height of a huge lightning storm yesterday after multiple reports of a drifting boat 300m from Carbis Bay.
The inshore lifeboat Colin Bramley Parker was launched into the harbour, "which looked more like a boiling cauldron than a sea", at 8.56pm.
Jonathan Harvey was at the helm, with a crew of Murray Walker and David Holland-Kemp, who was on his first inshore lifeboat shout.
A spokesman said: "They searched near Carbis Bay to investigate the situation, and reported that a boat was anchored in the bay, but there was no one on board and it was not in need of assistance.
The volunteer inshore lifeboat crew were then tasked to search the Porthmeor area as there were reports of a similar vessel in that area, but again nothing was found.
"The all weather lifeboat crew stood by with the boat on the slipway in case they were needed, but in the event were not called upon."