Crossing the line

Any guesses what this is all about?
 
Clue- it’s an ancient Norse ritual.
 
(I have to thank some friends of mine for this photo. We had lunch with them today in Perth and they had just returned from a Norwegian cruise).
 
The tradition is for all passengers making their first crossing of the Arctic Circle to get doused with ice and cold water. 
 
To add to the occasion one couple got dressed as Neptune and his bride while the crew were kitted out as pirates.
 
No, my friends didn’t get the water treatment, it was their second crossing of the Arctic circle, and they already had a certificate to prove it.