Iron boat rivets are commonly found in cremation graves. In some graves there are so many rivets that it appears as if the deceased was burned in a whole boat.
To burn a whole ship, which the ritual might have prescribed, would have been expensive. Just a few rivets might also represent a whole boat. Was this a way of creating symbolic ship burials and of expressing the cultural significance of boats? Women and men of different ages were buried in boat graves.
The tradition might have been associated with the god Frey, who owned the enchanted ship Skidbladnir. The boat was so big that there was space on board for all the Aesir gods, while it could also be folded up into a small parcel. It always had a tail wind; no oarsmen were needed.
Another explanation for the popularity of boat graves might be found in a tale from the Prose Edda of the burial and travel to the underworld of the god Balder. Balder was cremated in his ship in front of the other gods. The myth tells how he was mourned by all in Asgard. The gods sent Odin’s son Hermod to the mistress of the underworld, Hel, to ask her to return Balder. Hel promised that if the whole world wept for Balder she would release him.
The spiteful Loki, disguised as the giantess Tokk, refused to cry anything but dry tears so Balder stayed in the underworld with Hel. But the promise of the myth, that the return from the underworld was possible, may have made Balder’s cremation in a boat an archetype.