Viking skills at allowed them to cross the ocean in search of targets to raid

The Vikings, the guys who raided and pillaged much of Northern Europe, were successful because they are amazing shipbuilders. The Vikings invented the longship, a graceful, long and narrow, but lightweight wooden boat more often used for troop transports. The longships were very seaworthy ships, and it possessed a shallow draft enabling the ship to be sailed into rivers or beached into beaches so Viking troops can easily do amphibious landings on seaside towns or plunder more inland towns.