WATCH: Out of control speedboat flips after hitting rocks

Two speedboat passengers are lucky to be alive after they were sent flying through the air before landing upside down in an Idaho river.

The pair were competing in the annual Idaho Riggins Race, in the fittingly named ‘Maniac 313’, before they lost control and were sent hurtling straight into a set of protruding rocks.

As the boat became momentarily airborne, onlookers were left gasping as the pair vanished under the flipped boat.

Eventually the two yellow helmets emerged unscathed and the men clung onto the sinking watercraft before an emergency vessel arrived.

The pair were seen cheering as they sped down the Idaho's Salmon River. Source: YouTube
The pair were seen cheering as they sped down the Idaho's Salmon River. Source: YouTube
That's when things went very wrong, very fast. Source: YouTube
That's when things went very wrong, very fast. Source: YouTube
Onlookers feared the pair were trapped but they soon emerged relatively unscathed. Source: YouTube
Onlookers feared the pair were trapped but they soon emerged relatively unscathed. Source: YouTube

“Everyone was in complete shock, we were all just hoping neither of them were injured,” witness Jenni Stout told a local news agency.

“My heart completely stopped, I just kept thinking, ‘please be okay, please be okay’, waiting to see them emerge at the surface of the water.”