Depending on the weather, due to the arrival of Cyclone Hola, surf lifesaving crews will also do sweeps along the shoreline.
Waikato police Sergeant Vince Ranger, in charge of the search and rescue operation, said conditions had deteriorated overnight and he didn't think it would be safe for surf lifesavers to get out in the water.
"The conditions are very poor for any sort of searching but particularly by the IRBs ... yesterday it was building today it has deteriorated even more to the point where it's considered that it is a risky search for the IRBs to be involved out there.
"You've got a swell coming one way, you've got a wind chop coming another way, you've got rain and wind. Out in an IRB in those sort of conditions even if it was safe to get out all you're going to be doing is holding on to the boat."
However, there were two LandSAR crews - totalling six people - who would do the shoreline search, one group starting from the north the other the south.
That had its own risks, he said.
"We've got deteriorating weather and very remote and steep coastline searches. Homunga Bay is a beach there that's probably a couple of hundred metres long. But beyond that you've got rocky outcrops and steep bluffs up to the tops, basically. But it's very steep and very inaccessible."
Police believe the pair went missing from the southern end of the bay.