The lifeboat at Hunstanton has been launched to try to find a missing jet ski.
A spokesman for the coastguard said there was no-one on the watercraft at the time.
He said its owner had been trying to get it out of the water when it got loose.
The jet ski was not turned on at the time.
The lifeboat was launched at 5.32pm.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here