On the bridge of the cruise ship Pacific Jewel, a slip of paper is placed on the console in front of me. On it is written, "Ten minutes to mutiny site".
I continue talking into the console's microphone from which my words are being broadcast throughout the ship.
"By the night of 28 April 1789, Fletcher Christian's position on the Bounty had become intolerable. After abandoning his harebrained scheme to make a raft and leave the ship on it, he decided to take over the ship."
Another slip of paper appears. It reads, "Five minutes to mutiny site." I go on.
"Supported by others who had come to detest William Bligh, notably Matthew Quintal, Isaac Martin and Charles Churchill, at 5am Christian went to Bligh's cabin, held a cutlass to his throat and took over the command of the Bounty."
Pacific Jewel, a 70,000 tonne P&O liner, is in Tongan waters, carrying 1910 passengers and 621 crew, retracing the story of the mutiny on the Bounty.
I'm on the ship to deliver lectures on the mutiny and its aftermath. Many of the passengers have come on the cruise because of the Bounty theme.
Already we've called at Norfolk Island, home to many Bounty mutineer descendants, and there are also mutineer descendants on Pacific Jewel. This morning, at 0950 hours, the ship is following precisely the course taken by the HMAV Bounty in 1789.
A third slip of paper appears. The message reads, "Mutiny site reached."
I announce, "Directly below us, at 19 south latitude and longitude 174 west, the mutiny on the Bounty took place."
The tall, immaculately uniformed captain of Pacific Jewel, Canadian Tod McBain, takes over the microphone, which I'm sharing with him and David Pepper, the cruise director.
The Captain announces to the ship, "Unfortunately we're unable to stop the engines here, due to wind and sea conditions, but we've passed over the mutiny site. And in a moment we'll be altering course slightly and heading for Tofua Island, 28 nautical miles NNE."
Captain McBain, David and I are all Bounty mutiny aficionados, fascinated by this great sea story and its many repercussions.
Staring down from Pacific Jewel's spacious bridge, hundreds of feet above the mutiny site, naturally the sea here looks no different from any other area of the South Pacific ocean. Yet in the annals of royal naval history this place's provenance is unique.
Bending again to the microphone, I say, "There should be a huge marker buoy placed right here, with William Bligh's image on one side and Fletcher Christian's on the other, for the benefit of all passing ships and yachts."
David Pepper and I differ about the relative merits of Bligh and Christian.
As an ex-Royal Navy man, David has no time for mutineers.
"And," he points out, "Bligh was a superb navigator and hydrographer."
This is undeniable. Bligh's post-mutiny feat of getting 18 men across the open sea from these water to Timor, 3618 nautical miles away, was exceptional.
But his courage and strong sense of duty were outweighed by his vindictiveness, verbal abusiveness and hypercriticism of others.
I point out to David that, "Bligh's men preferred to be flogged with the cat o' nine tails, rather than be lashed by his poisonous tongue."
"Words, just words. Christian should have toughened up."
I persist in defending Christian, Bligh's young acting lieutenant.
"Remember, he'd had to leave his lover, Isabella, behind in Tahiti, and she was pregnant with their child."
I just can't help but side with Christian. I've recently been on Pitcairn Island, where Fletcher (or "Flatcher", in the islanders' distinctive dialect) is still accorded heroic status by his many descendants.
It is the same on Norfolk Island, to which many descendants of the mutineers from Pitcairn moved in 1856.
"No," I aver, "Bligh made Christian's life unbearable."
Captain McBain has been listening closely to this discussion. First making sure the microphone is switched off, he says to David and me, "I know we're in the exact position, but you two aren't going to re-enact the mutiny on my ship, are you?"
He smiles. "And I did take the precaution of locking my First Officer in his cabin this morning."
Earlier that morning, Captain McBain had provided the commentary as the ship cruised alongside Nomuka, a low island in Tonga's Ha'apai group, where the incident occurred which sparked the mutiny.
As Master on James Cook's Resolution in 1777, William Bligh had called at the island to take on supplies. So 12 years later he felt confident about anchoring the Bounty off Nomuka and sending a landing party ashore, led by Fletcher Christian, to gain provisions.
But the Friendly Isles, as Cook had named them, were now distinctly unfriendly. Cook had deeply offended the Tongans by taking two chiefs hostage and treating them in a humiliating manner, and 12 years later, the locals still remembered this grievous insult.
Consequently, the Bounty's shore party was attacked, and although they carried muskets, Bligh had specifically forbidden Christian to use them.
Upon his return to the Bounty, Bligh gave Christian a tongue lashing in front of the other men, accusing him of cowardice. Although he ordered his men flogged less often than most naval captains, Bligh's tongue was wounding. Christian was humiliated, and bitter.
To make matters worse, the following day, again in front of other members of the crew, Bligh accused Christian of stealing a coconut from a store.
His honour twice impugned, this was too much for Christian, and it took only a phrase of encouragement from American seaman Isaac Martin ("By God, I am for it!") to precipitate mutiny.
Pacific Jewel heads for Tofua, Tonga's westernmost island. Half an hour later a grey smudge appears on the horizon, then Tofua's profile becomes clearer, shadowed by the perfect cone of neighbouring Kao (1046m), Tonga's highest island. A past eruption has decapitated Tofua, but it's still active and smoke can be seen drifting from its crater lake. Humpback whales breach nearby.
After Bligh and his loyal men had been set adrift in Bounty's crowded launch, with only 17cm of freeboard, they first headed for Tofua, seeking provisions for the arduous voyage which lay ahead. But the locals here were hostile too, and after tethering the launch to a grapnel and spending one night on the island, the following day the Englishmen were attacked. Bounty's quartermaster, John Norton, was killed but the others just escaped and set sail to the northwest.
Staring at Tofua's rugged, wave-lashed coastline and steep, forested slopes, it seems amazing that Bligh managed a landing here at all. We take one last look at the volcanic island, then Captain McBain sets Pacific Jewel's course for the northwest, in the direction of the Fiji islands, just as Bligh did, 222 years earlier.
During my last lecture I put up on the ship's screen a portrait of Bligh and an image of Christian, constructed from what it is thought he looked like.
Too young at 23 to have had his portrait painted before he signed on to the Bounty, the image is of a dark, handsome, brooding young man.
And that evening, in the ship's auditorium, David Pepper puts on a special screening of the 1984 movie, The Bounty, starring Anthony Hopkins as Bligh and Mel Gibson as Christian, in my opinion the best of the five Bounty mutiny movies that have been made.
The audience is transfixed by the film. And now they can all say, "I've seen where the mutiny happened, and the movie."
Getting there: Pacific Jewel will leave from Sydney for its Mutiny on the Bounty Cruise on October 7 and return on October 23.
Further information: See pocruises.co.nz.