A MISSING Tully spear fisherman was just metres from the surface with his final catch when he suddenly vanished on Monday, a nearby boatie has revealed.

Innisfail fisherman Larry Jones told yesterday how 21-year-old Sam Hyytinen, whose disappearance has sparked a full-scale police search, had free-dived about 22m one last time to retrieve a lodged speargun with a mangrove jack on the end.

Mr Hyytinen went missing at Otter Reef on Monday afternoon, about 26 nautical miles off Mission Beach, south of Cairns.

"His mate told us he could see him a couple of metres under the surface but then he stopped coming up and disappeared from sight," Mr Jones said yesterday. "It had been a long day. He'd caught 14 fish and I believe he may have pushed himself too far.

"He (the mate) jumped in but he couldn't get down to reach him without any lead weights.

"He was devastated."

Cairns Water Police Sen-Constable Nathan Johnson confirmed the missing man had been gasping for air when he came up from the previous dive, but said he had rested in the boat about 15 minutes before descending again.

"He went down again to get his speargun," Sen-Constable Johnson said.

Mr Hyytinen’s friend, a Tully man in his 40s, set off flares, radioed for help and raced to Mr Jones’ nearby live trout boat.

"We sent all the dories out on a grid pattern until they ran out of fuel," Mr Jones said.

Police divers from Brisbane yesterday joined an extensive air and sea search that began on Monday and will resume this morning.

Emergency Management Queensland rescue helicopters from Cairns and Townsville were also on the job, as were coast guard crews from Tully and Cardwell.

The divers returned to Mission Beach after dark last night, with no news for anxious family members despite battling strong currents to scour the last known location of Mr Hyytinen.

They were planning to speak to local spear fishermen and bring several with them on the search today.

Sen-Constable Johnson said the missing man, who is believed to work at Tully Sugar Mill, was an experienced diver who had been wearing a full wetsuit, weight belt, fins and snorkel.

Last night's search was called off about 9pm and today’s effort is expected to involve a fixed wing aircraft rather than helicopters and will again concentrate on Otter Reef.