Sei whale sighted

Sub-title / Description

Rarely spotted Sei whale in Manx waters

In January 2025 we were contacted by Derek Lumb who had been looking through old photos from his sailing trips in order to put together a presentation. Derek then submitted this sighting from four years ago, on 9th July 2021, of a small minke whale (3rd photo) accompanied by a much larger whale (1st and 2nd photos).

MWDW can confirm that these photos are of a Sei whale. These are a large rorqual with a distinctive curved dorsal fin and body length of up to 19 metres. When surfacing, the double blow hole and dorsal fin are seen at the same time.

Due to their similarities with a large minke and a small fin whale, many reports of Sei whales go un-recorded making it a very difficult species to study.

Sei whales are rarely sighted in Manx waters, and until now, no good quality images had been taken of this species here. However, we have always been aware of their possible occasional occurrance. Indeed, they have been here historically, and the skeleton in the Manx museam is that of a Sei whale which stranded in 1925.

On one occasion about 4 years ago, MWDW observers were watching minke whales from the coast at marine drive and observed one particular whale displaying a ‘skim feeding’ behaviour, which is indicative of a Sei whale. 

Whilst further possible sightings have occurred over the years, these excellent photos sent in by Derek provide the first sure evidence that this species do include Manx waters in their range.

We are grateful to Derek for sending in this sighting and to everyone who reports to our public sightings network.

More on rare species

Find out more about rare species in Manx waters