Which whales you actually see from Reykjavik, and how to tell them apart

Minke whale. Eight to nine metres, dark grey-brown with a pale band across each flipper, and a small curved dorsal fin about two thirds of the way down the back. The blow is low and often invisible in wind. What you usually see is a smooth roll: fin, back, gone. Minkes are curious and will sometimes approach a drifting boat, which is when people realise how big eight metres actually is.

White-beaked dolphin. About three metres, with a pale grey saddle and a stubby white beak. They travel in groups of five to twenty, move fast, and break the surface repeatedly rather than once. They are the most reliable sighting in the cold months and the most likely animal to come to the bow.

Harbour porpoise. A metre and a half of dark triangle that appears for half a second and does not come back. Common in the bay, seen far less often than it is present, and the sighting most likely to be missed by everybody except the crew.

Humpback whale. Thirteen to fifteen metres, with a tall bushy blow you can see from a kilometre away, long white flippers, and the fluke lifted clear of the water before a deep dive. That fluke is the photograph everybody wants, and its underside is individually patterned — researchers identify individual animals from it. Humpbacks are the ones that breach, and a breach in Faxaflói empties the deck of conversation.

Nobody on these boats is scanning the water at random. Three things do the work.

Birds. Gannets diving vertically and kittiwakes rafting on the surface mark a shoal of sandeel or capelin, and a shoal marks a feeding whale. The crew are watching birds long before they are watching water, and so should you.

The radio. The boats in this bay talk to each other. A sighting from one hull is passed on, which is why you sometimes see three vessels converge on the same patch of water. It is co-operative rather than competitive, and it raises everybody’s odds.

Patience. A whale surfaces to breathe several times in a row and then dives for five to ten minutes. Experienced crews position the boat where the animal is likely to come up, cut the engine and wait. The temptation for passengers is to look where the whale just was; the trick is to look at a wide arc of water ahead of it.

There are rules about how close a boat may approach, and reputable operators keep to them — the animals come closer of their own accord surprisingly often, and a drifting boat with the engine off is what makes that happen.

Iceland is one of a very small number of countries that has continued commercial whaling in the modern era, and visitors often arrive aware of that and unsure what it means for a whale watching trip.

The two industries are separate and, in Faxaflói specifically, they have been in open conflict for years: whale watching operators have campaigned for the bay to be a permanent sanctuary, on the straightforward grounds that the animals their passengers come to see are the ones being hunted. A large part of the bay has been designated as a no-hunting area for exactly that reason.

Domestic consumption of whale meat in Iceland is low; the market has historically been export and, to a degree, curious tourists. The campaign that asks visitors not to order it in restaurants — you will see the sticker in windows around the harbour — is run by Icelanders, not by outsiders.

None of this needs to be part of your afternoon on the water. It is worth knowing because the guides will sometimes talk about it, and because the sentence that surprises visitors most is that the whale watching fleet in this harbour is on the same side of the argument as the people who booked their tickets.