A US shipbrokerage is asking for companies to float offers after an innovative hovering vessel that remained unfinished for years was finally named.

The 450-tonne-capacity hoverbarge Ghost is "ready to work" after commissioning and hover testing, said Marcon International, the Washington state shipbrokerage that is marketing the vessel.

With 836 square metres of clear deck space, the Ghost is thought to be the world's largest hoverbarge.