This article introduces some of the many finds of nautical interest from Birka
https://www.sea.museum/2016/04/29/maritime-archaeology-at-the-viking-age-site-of-birka
A very interesting length of rope that would have been tied round a stone to anchor ships in place.
and if you are interested in a boat to go with tou anchor – Whithorn Rebuild with Gail McGarva will be launching this one in a few weeks time. Get yourself along to Whithorn!
https://www.facebook.com/share/p/JGGyVQkqEwoCazpH
If you can’t make it for the Launch on fridag, there is a whole weekend of fun at the Whithorn trust where you will be able to get close to the boats.