I have collided with unknown vessel.

我船和一艘不明船相碰。

youdao

The vessels are taken over by armed pirates and then forced to sail to an unknown destination, where the cargo is discharged into a smaller tanker, and then the vessel is brought back and released.

船只被持有武器的海盗劫持，被迫驶向未知的目的地，货物被分装到小一些的油轮，然后，船只被带回并获释。

youdao

The Museum of the Unknown is a vessel.

未知博物馆是一个容器。

youdao

Not so lucky were the shipwrecked crew of an unknown vessel washed up in 1860.

BBC: The ghostly shore of Namibia��s Skeleton Coast

"The potential for a pollution incident is unknown at this time, but officials have limited concerns about any biological threats due to the length of time the vessel has been at sea, " the Coast Guard said in a statement.

CNN: U.S. Coast Guard sinks Japanese boat washed away by tsunami