Board Thread:Questions and Answers/@comment-108.201.159.35-20151125231659/@comment-26107364-20151126102456

to elaborate, even if a ship only drops in an event map (either as a completion reward, or as a combat drop) there is precidence that they will return as a drop in future events and/or as a construction possibility a longer time later.

The Fog ships were event-exclusive to the Winter2013 event, and were removed from the fleets of everyone who participated at the end of the event.