WHALE-WATCHING CAN BE a tedious business - sitting around until long after your bum goes numb, staring out to sea hoping beyond hope to see a blow or a dorsal fin.
Waves become an enemy of distraction, as each one quickly becomes a manifestation of a potential fin.
I have sat for hours waiting patiently for whales or dolphins to show. If they do, its usually about 10 minutes before we have to head for home.
Then I went looking for beluga whales, and the boat had barely left the harbour when the first white backs appeared. Soon we were surrounded.
The small town of Churchill in Manitoba, Canada, is world-famous for its autumn sightings of polar bears.
They gather here to await the formation of the Hudson Bay sea-ice on which they hunt seals - making the town the polar-bear capital of the world.
Churchill exists because of the Canadian grain industry and now tourism. People in this frontier town work in one or both sectors. There is a supermarket, several good eateries and a few hotels, but no partying.
In October the town is busy with bears, and the people from across the globe who come here to watch them.
But Churchill has a summer secret for anyone who loves marine animals. Thousands of beluga whales come into the Churchill River to hang out, give birth and mate during July and August.
They feed on caplin (small fish that breed in the shallows during summer) and enjoy the warm river water.
This is several degrees warmer than the Hudson Bay into which the Churchill empties, so newborns dont need too much insulating blubber.
Babies are about 60cm long, and resemble a light grey sack of bones. They soon fatten up, and lay down insulating blubber to match that of any burger-muncher. Within a couple of weeks they are venturing into Hudson Bay with their mothers and the bulls, which feed on the influx of caplin.
The newborns hang with their mother, staying above her for the most part, because with their smaller lungs they need to breathe more often. The mother tends to break the surface first, closely followed by the baby.

THE BELUGA WHALE WAS FIRST DESCRIBED by Peter Simon Pallas in 1776, and took on a mystical role in many northern sailors lives. Pallas was a German zoologist working in Russia, and the name beluga comes from the Russian belukha, itself derived from belyy, which means white.
Adults are brilliant white, but the young are slate-grey until the age of about three, when their skin lightens and they become mottled. The species is distributed across the northern hemisphere, and belugas were often encountered by men trying to navigate the north-west passage. They were nicknamed sea canaries for the high-pitched squeals and whistles they use for both communication and echo-location.
The beluga is also the only marine cetacean (which covers whales, dolphins and porpoises) that can turn its head.
Where most cetaceans have fused neck vertebrae, belugas are mobile, the same as humans and most other mammals, as well as river dolphins.
So belugas can turn their heads to look at you, and for anyone who has studied dolphins that is horror-film-statue-turning-its-head freaky.
I knew they could do it, but the bizarreness of the trait didnt hit home until I was under water, watching a large male approach me.
It got alongside, and then turned to look me right in the eyes.
Getting in the water with belugas is simple, if you follow the rules. Small whales are on the menu of killer whales, Greenland sharks and polar bears, which naturally makes them nervous of the unfamiliar, but they are also incessantly curious, and love to follow boats.
This has led to the development of towed snorkelling. When the whales are around the boat, they follow it for quite a while and approach exceptionally closely. So tour guides tether ropes to the side of the inflatable and slowly pull snorkellers along. The whales become fascinated by the new growth on the boat, and come to investigate.
At around 8-10°C, the river water is a decent temperature for either a thick wetsuit - which is what the tour companies rent to guests - or a drysuit, which is what I used. A hood is essential, but if the weather is good only thin gloves are required. Because the boat is pulling the snorkeller there is no need for fins. Just dont let go!

MOST OF THE WHALES ARE FOUND well inside the river, where the water is warmest, but murky. The Churchill River runs for 1000 miles through forests, farmland and tundra, and picks up sediments from all habitats.
By the time it reaches the sea in the south-west of Hudson Bay, it is loaded with particles and consequently greeny-brown - good enough for snorkelling on a good day, but only just.
For beluga whale-watching, the river area is fantastic, because there are thousands of whales all over the place. The best place to see them under water is the river-mouth, or even in Hudson Bay itself. Diluted with sea water, the water here is greener and clearer, so the whales are easier to see, the only problem being that they are less concentrated.
During the ebb tide, the whales were generally heading out of the river into the bay to feed, but they would readily break their journey to play with a small rubber boat with a strange biped holding onto the side.
The river-mouth is quite narrow, and protected by highish ground on both sides, so the water can be calm when its rough elsewhere.
When it does kick up, beluga-watching becomes a challenge, but I was blessed with generally good weather.
The previous week, a BBC film crew had been disappointed by the conditions and lack of decent filming opportunities.
My best photo session was in Button Bay, on the far side of the headland opposite the towns port.
In calm, clear water we hung around with a pod of about 10 males as they fed and then rested in the sunlight.
It was baking - not what I expected in a sub-Arctic region. But at 58°N, Churchill is only a little further north than Aberdeen, and located on the North American continent, which warms up like a hotplate in summer.
Sweat ran down my face as my drysuit insulated my body. I left the boat like a baked potato in tinfoil, so the cool water was both a shock and immensely pleasurable.
Holding onto the line tied along the inflatable pontoons of the boat, my cox motored slowly forward towards the surfacing pod. Caplin scattered like glittering confetti thrown upward as they tried to escape the rising predators.
The dark water around me grew ever-lighter as the white whales approached, and as they came out of the depths they blew bubbles before hitting the surface to take a massive inward breath.
They saw the boat and ambled over to check us out - passing so closely at times that I could see every wrinkle and scrape in their skin.

PHYSICAL APPEARANCE APART, the most striking aspect of belugas is their voice. Well, less a voice, more an orchestra trapped inside a white bag. Researchers have recorded more than 50 vocalisations, made up of whistles, clicks and squeaks.
Their echo-location also pings off when investigating an object, and I could feel the percussion of vibrations as the whales approached. Using their large and strangely malleable melons (the bulbous part at the front of the head), they focused the sound waves to gain an accurate picture of me and the boat.
Some whales were bold; others hung back, or swam below, turning on their backs to look up at me. Their ghostly forms flared against the dark green of Hudson Bay. They were mostly bulls, all pure white, but a juvenile and a mother and calf were close by.
The calf rode on top of its mother, just behind the dorsal stump area. Unlike most cetaceans, belugas have no dorsal fin - a bid, scientists believe, to conserve heat under the ice floes where they spend much of the year. In this position, the calf is forced to follow when the mother goes to the surface to breathe, so the mother breaches first.

AT THE SURFACE, belugas are easily seen as light patches in the water, but their eyes generally stay below the waterline, and spectators see only a blow and the white of the back.
They show more when the sea is choppy, as they have to get their blow-holes high above the waves to take a breath in safety.
Whales take around three breaths in fairly quick succession to expel CO2 from their blood and enrich it with enough oxygen for a dive that lasts several minutes. On descent, they let a lot of air out of their lungs to reduce buoyancy, so the dive is less strenuous.
I know that belugas are acutely adapted to the marine environment, but nothing was hurried about the surfacing or diving - there was no frantic activity, even around boats.
Researchers monitor the whale populations each summer to ascertain whether the tourist industry is having a detrimental affect, but so far at least there is little if any evidence of this.
The number of tourists who reach Churchill is comparatively low, the boats the operators use are small, and the coxns are highly skilled at minimising intrusion. These factors, combined with the whales inquisitive nature and their contentment in their surroundings, probably leaves them unstressed.
This is not true of belugas elsewhere in the world. The St Lawrence River population, for example, is threatened by industrial pollution that has lead to cancers and other serious illnesses in the dwindling population. It was this population that prompted the IUCN Red List of Endangered Species to list belugas as Vulnerable, a mere step from being Endangered.
For now, at least, the Hudson Bay population is healthy, and numbers around 25,000. Lying face down in the water watching a whale a couple of metres below me looking back, it was easy to forget what mankind is doing to this enigmatic species.
Belugas were the first whales to be taken into captivity, and it is still one of the few whale species being kept in aquariums. I recently saw two in a horrendous animal park in Jakarta, Indonesia; a couple of years ago there were two more in a dolphinarium in Sharm el Sheikh, Egypt, and more recently British newspapers carried a story of a whale in China being forced to swim with a four-year-old boy.
It looked happy, as do all the whales and dolphins in captivity, but then nature made them that way - bored, depressed, sad or joyful, the beluga can only smile. Its a hideous indictment of what humans will do for entertainment.
In the wild, belugas are endearing and fascinating creatures, and you dont need to stalk them, or wait for hours just to get a glimpse. They are on show for the world to see, so why imprison them for our gratification Beats me.

Sea North Charters offers beluga-watching excursions and snorkelling from a Zodiac, which costs around £100 for two hours, www.seanorthtours.com. From Winnipeg take a three-hour flight to Churchill on Calm Airlines (www. calmair.com) or a 36-hour train ride. Gavin Parsons stayed at Churchills SeaPort Hotel: The rooms are very comfortable, basic, but clean and the staff are incredibly friendly and helpful.