What they used longships for?

Vikings long-ships were very useful to them. The pirates used them raiding contrys slaughtering everyone and traiding alot. Viking long-ships could sail in rivers,lake and in shallow water.

How they made the long-ships?

Most pirates built the mean horrific boats near rivers. Keel were made from oak trees it was built at top of the boat. Wood (oak) was the most useful they used them for the planks,seats and ribs.