Hawke's Bay officials are monitoring for any pollution issues after a boat partially sank off the port yesterday

Four men were rescued when their 10.5 metre boat hit a submerged log and started to sink around 3.30 yesterday, with 500 litres of diesel fuel aboard.

The group was one of more than 100 taking part in the annual Megafish tournament at the time.

Numerous boats, including Port of Napier pilot and tug boats, were on the scene quickly to rescue the men.

The vessel was towed to Napier where it will be lifted from the water by crane.