Coastguards are concerned for the safety of a couple whose yacht is in trouble in horrendous conditions off Whangarei.

They've been battling gale force winds, rain, and waves of up to six metres.

The couple ran into trouble sailing their 12-metre yacht between the Bay of Islands and Whangarei, and reported problems with their steering last night.

Coastguard duty officer Mark Leevers says several boats have tried to reach the pair, but had to turn back because of very rough sea conditions.

He says the two of them will be extremely tired and well beaten by the sea.

Mark Leevers hopes Coastguard will be able to provide some assistance to them.

A helicopter is going up at first light to work out their exact location.