Two men have been found dead inside a twin-hulled catamaran drifting off the central Queensland coast.

Key points: Police say the boat hit a submerged object, but they don't know what it was

Police say the boat hit a submerged object, but they don't know what it was While the boat was travelling quickly, its speed was not believed to be excessive

While the boat was travelling quickly, its speed was not believed to be excessive Seas were calm, but the area was affected by smoke haze

Police said a 39-year-old man from Emerald and a 59-year-old man from the Mackay area were found dead inside their six-metre aluminium power boat.

A passing vessel spotted it drifting near the mouth of Island Head Creek at Shoalwater, north of Yeppoon, about 11:30pm on Friday.

Police said early inquiries suggested the men's boat hit an object in the water at speed, causing a significant amount of damage to its bow sections.

It is thought the men were killed in the impact, however the exact cause of their deaths is yet to be confirmed.

Damage to boat's hull which was found drifting at night near the mouth of Island Head Creek. ( Supplied: Queensland Police Service )

Sergeant Shaun Halson from Yeppoon Water Police said conditions in the ocean were calm around the time the incident occurred.

"At this early stage of our investigation, it's clear that the vessel has struck a submerged object," he said.

"It has struck it at speed, however there is nothing to suggest that speed was excessive.

"The nature of that area, even at cruising speed, could cause substantial damage. As a result of hitting the submerged object there has been impact inside the cabin."

Police will salvage the boat for inspection over the coming days. ( Supplied: Queensland Police Service )

Sergeant Halson said they did not know yet what the boat struck, but that police would salvage the boat for inspection "over the coming days".

"The operators knew the area, so it's still at the early stages of our investigation as to how exactly it transpired," he said.

"That area is characterised by lots of small, rocky islands and lots of submerged objects.

"The sea conditions were calm, however the area was suffering from smoke haze.

"The westerly winds were blowing a large volume of smoke from the inland grass fires out over the sea, so that will form part of our investigation."