Chico, It's a pity Operation Hornbeam isn't still going. I'm sure you'd have loved it. Ship spotting on the coast, looking for Soviet merships... you know, typical merchant vessels with NBC on deck washing-down facilities and gas-tight iron doors and hatches to protect the fish from the smell of capitalist air!
Now get your parents to buy you the latest edition of Janes Fighting Ships (the one covering WW2 is less depressing though) and a decent pair of binoculars (Leica's
Duovids are excellent, even in poor light!) and buy a folding chair, a large Thermous flask (filled with hot coffee or soup) and a thick submariners pullover, visit Pompey and have a good Christmas gazing at the naval traffic. You could also take the opportunity of looking for the shapes (daytime) and lights (night) on the vessels indicating their size, status, etc.