Complex sentence: They were also used (but rarely seen) in a few episodes of' when shipboard crises forced the crew to flee the title vessel, though they were eventually able to return to the ship once the danger had passed.
Split into simpler sentences: They were also used (but rarely seen) in a few episodes of' when shipboard crises forced the crew to flee the eponymous vessel. Often the crew were able to return to the ship once the danger had passed.