Games or hobbies quiz

[keyboardix]

I invite help to solve the following 3 clues, please. No "letter-count" is given for the answers.

12. The net or the waves.

30. Tom goes in off the deep end.

31. Hide and seek containers using a GPS.

[johnalex]

12. Surfing

[Ouzel]

30. Diving ? Tom Daley perhaps.

[treetops1]

31. Geocaching

[keyboardix]

Thank you all for your very quick replies. The suggestions for 12 and 30 I understand, but, with respect, treetops1, in all my years I have never heard of "geocaching" ( for 31). I wonder if I am missing something ?!!!? Nevertheless, thank you all, again.

[treetops1]

http://www.geocaching.com/