At the beginning, Mac "introduces" his landlady (Susan) as if she's new. But in the previous episode he's playing table top hockey with her, indicating they were shown out of production order. Although she was apparently meant to be a recurring character, she would never appear again.
This episode follows the plot line of the 1974 film "Juggernaut", which itself was based on a real life incident involving the Cunard liner "Queen Elizabeth II".
The cruise ship nominally referred to in the episode as the S.S. Victoria was, in actual fact, the M.S. Vistafjord. Partially constructed in France and then finished in the United Kingdom after her construction cost put her original builder out of business, Vistafjord was the last cruise ship to be built in the UK.
Pete says that Mac was in Vietnam in a bomb disposal unit. He wouldn't have been there for long, as he was a college senior in 1973, and by the time he would have gone through basic training, etc., and sent out to his new station, the American involvement there would be practically over.
It is revealed that MacGyver never plays golf.