My humps: one journalist's encounter with the beef of the sea - and Terri Irwin

Someone spots a blow spout six nautical miles from the coast. Wait 10 minutes in almost total silence but turns out to be nothing. Captain Shane says humpbacks are "elusive creatures".

Heading for humpback highway, about 10 nautical miles from shore, where chances are supposed to be better. Three people have turned green and are sheltering from the sea spray inside lower deck of boat, which is starting to feel like a height-restricted ride at Dreamworld or the drum of a Fisher and Paykel top loader. Suspect more than one will be riding the vom train home.

Our first sighting. A stone-coloured lump with a dorsal fin surfaces 150 metres away on starboard side, but quickly disappears. Then a tail. My stomach does a quick flip-flop, but this may be the fault of a rogue wave. Gasps from the boat as two more whales are spotted on the horizon, but me and the Canon are not quick enough.

Surprise whale fact: blue whales are so big they have an artery "that a small child could fall down". Suddenly, Jonah's biblical ordeal doesn't seem quite so far-fetched.

Hoping to be mugged on port side, which in whale-watch parlance, means to be examined up-close by a whale that has approached the boat. Captain Shane has spotted a pod of three up ahead and informs us they may be engaged in some mating activity. Not sure if I will be able to look them in the eye if this turns out to be the case. He opens up the throttle and we go over to intrude.

Crowd on lower deck is growing, where Quells are being popped like Smarties and one person is lying slumped in a chair. Starting to regret that drive-thru bacon and egg McMuffin.

Pod of three turns out to be a party of five, each bobbing up for air in sequence; three then one, then another. The bow is buzzing as we all lean over the rails (think Kate Winslet with a digital camera) to get closer. The woman next to me - Cybershot poised - mutters "come on babies" and then it happens; less than 150 metres away a humpback launches itself from the water, its barnacled bulk twisting and arching in a 180-degree back-flip. The spectacle is called breaching, and within minutes, all five of them are at it. Spray shoots skyward like fireworks as the whales hit the water, which is turned turquoise against their exposed white bellies. Sixty-five tonnes in all. Magnificent.

I'm machine-gunning anything that moves when it occurs I may be having a once-in-a-lifetime whale encounter entirely through the lens of a digital camera. Look around and notice everyone else is doing exactly the same. Decide this is stupid and holster the thing for a minute to enjoy the experience as my ancestors would have done, in the days before 1-gig memory cards were invented.

Captain Shane says humpbacks can follow the same pattern of behaviour for hours, as ours are doing now. Spouting, bobbing, bobbing, diving and then an explosive, 2000-calorie-burning breach. He suspects a group of four blokes is showing off in front of a sheila, who must be plus-sized as - in a refreshing contrast to our own dating scene - fat whales are considered hot. We follow them for a while, but the flash of their tails signals a deep dive and we don't see them again for some time.

I let the profession down by managing only a single roast beef roll at the all-you-can-eat lunch buffet. Regret queuing for Arnott's Creams instead of Quells.

Captain Shane hangs a u-turn and warns watchers on the bow they are likely to get wet because the journey back "may be a bit rough".

First sighting of a sick bag. Port side.

Did I mention I should have taken some Quells?

Hobble down gangway towards car park and a 100-kilometre drive back to Brisbane, fighting the urge to dispose of said roast beef roll in a potted palm.

Home for a lie down. Upload photos and instantly forget churning stomach. Can't believe I was there. Magnificent.