In Shetlandic folklore, a type of fish or whale that destroyed boats by diving and coming up under them, smashing or capsizing them. Fishermen rowed a zigzag course to escape them. They were very much dreaded, especially when one was seen alone. Formerly, when they saw one, they prayed to it to leave them alone, and made offerings or payments of small silver coins. Another approach was to hold a copper penny in the water and scrape it with a steel knife; this protected the boat and the sjafer would not approach.
Similarly, the fjaedin or finner (finner-whaal, or fin-whaal, i.e., herring-whale) was also said to occasionally destroy boats.
Presently the sjafer is identified with the grampus or the thrasher.
- Spence, J. (1899). Shetland Folk-lore. Lerwick: Johnosn & Greig, p. 122.
- Teit, James A. (1918). "Water-beings in Shetlandic Folk-Lore, as remembered by Shetlanders in British Columbia." JAF 31:180-201, p. 197.