Minke whales are by far the most common species seen in the bay, with regular sightings of white-beaked dolphins, humpback whales, and porpoises and less frequent appearances by orcas, fin, sei, or pilot whales, and the 'big one' - blue whales.
It takes about an hour to sail to the prime feeding grounds, where crew and participants get busy looking out for telltale signs of a surfacing whale. Although whale watching tours boast impressive success rates for sightings (95% to 98%), whales do not always appear on cue. Sightings are announced using a 'clock' system, with the stern of the boat at 12 o'clock.
Different whales have different habits and identifying features. The curious minke whale surfaces two or three times in quick succession before executing a deep dive and sometimes may even approach the boat. Humpback whales breach and sometimes roll over, holding an enormous flipper in the air. Most whales arrive in Icelandic waters in spring (around May) and stay to feed until September when they return to warmer southern waters for breeding.
In town, there is also a civic museum about culture and biology. Among other things, it shows a stuffed polar bear (arrived in Grimsey in 1969) and some ancient boats. Enjoy your visit!