Isaiah Dixon, Thomas Courto and Bree-Anna Thomas, who are all from the northwest, left Wynyard on a yellow and white 17-foot Caribbean around midday on Monday.

They were reported missing by family that evening when they failed to return as planned.

Police discovered the bodies of Ms Thomas and a man, who is yet to be formally identified, washed ashore near nearby Table Cape on Wednesday afternoon.

"The family ... have expressed their gratitude for the searches and particularly to the Wynyard community, who've been there in their time of need," Inspector Steve Jones told reporters.

Extensive land, aerial and sea search efforts to find the second man and the vessel were expected to go late into Wednesday evening.

"We've narrowed it down to a search area and we'll be narrowly focusing on that," Insp Jones said.

"We always hold hope that we are going to find people alive, and that's what we'll continue to do."

Members of the northwest community were advised against taking their boats out to help the search on Wednesday due to rough conditions.

Volunteers used their own boats in Tuesday's efforts, with one person donating $500 worth of fuel to anyone who could go out.

Police vessels and helicopters, plus SES crews on land, resumed searching at first light on Wednesday before the two bodies were spotted from the air.

Insp Jones said meetings would be held on Wednesday evening to consider Thursday's search plans.

The boat, believed to belong to Mr Dixon's father, was equipped with required safety equipment including flares, radio, EPIRB and flotation devices.

Their boat was last seen on Monday anchored in Boat Harbour, northwest of Wynyard, and there is no hint of suspicious circumstances.

Mr Dixon held a boating licence, police have said.

Mobile phones belonging to the trio have not returned a signal since Monday afternoon.

Australian Associated Press