Boaties travelling in the Eastern Bay of Plenty are being urged to be careful crossing the bar as it is traditionally shallow at this time of year.

Bay of Plenty Regional Council's Eastern Bay harbourmaster Brian Spake urges boaties to take more caution when crossing bars.

Image: Google Earth.

"In most cases the bars become shallow as a consequence of reduced river flows. The ÅŒhiwa harbour entrance is currently the exception and it has good depths at the crossing point.

"Thornton and Ōpōtiki currently have restrictions in place. You shouldn't cross the bar three hours either side of low-water for Thornton and two hours either side of low-water for Ōpōtiki."

Brian says boaties must adhere to restrictions and if swells are present remember the under keel clearance is further reduced.

The Ōhiwa and Ōpōtiki entrances are currently lying respectively in a north-north-west and north-west direction. This is where the deeper water can be found for crossing.

"Thornton is a little more unpredictable", says Brian.

"It is subject to small shifts in direction. However as Whakatāne is a controlled entrance it is a more reliable with current depths at 1.6 m at the lowest astronomical tide.

The harbourmaster advises all visitors and those unsure about bar configurations to use Whakatāne entrance or seek advice from a regular user prior to any crossing.

"Also remember a suitable lifejacket must be worn at all times when crossing river/harbour bars."