Bay of Plenty's beaches are filling up with swimmers and sunbathers and with high tide about to hit, surf lifesavers are urging people to be safe in the water.

Mount Main Beach. Photo: file.

Omanu's director of lifesaving Dennis Mundy says there's about six times more people on the beaches today compared to yesterday.

'The surf is cleaned up far, far better than yesterday and looking far more attractive.”

Dennis says high tide is at 12.05pm today, with 1pm the critical time to avoid trouble in the water.

He says there's been no rescues as yet, but surf lifesavers are on high alert at Arataki, Tay St and Omanu beaches as well as Mount Main Beach. 'It's going to be a big day.”

The warning comes after five people were rescued at Tay St beach and another two people at Arataki yesterday.

An IRB from Omanu rescued five people, including a father of two at Tay St beach, while another IRB performed a second rescue of two others.

Dennis' advice is for people to stay well within their depths, listen to the lifeguards and swim with groups.

'Just be very careful today they are dangerous conditions, it's as simple as that.”