Possible Clues:

• Serve alcohol in a quandary — might one be 16 or 18?
• Coach is relaxed about husband
• Son and husband boarding reserved coach
• Trainers chase horse and colt all over the place
• Second husband boarding air-conditioned train
• Body of artists knocking back a litre, alcohol's drunk
• Teach swimming group
• It might be primary or parochial
• Group of fish, porpoises etc
• Strangely, loco's hard to start for train