I'm on the minimed pump and cgms and working in a hospital i'm always careful not to go in the MRI room (strong magnets are bad for pumps, and dangerous if the magnet attracts the metal in the pump and pulls it out of you and flying across the room).
One thing I had never though about until my fabulous diabetes educator filled me in was that the anti-gravity rides where you ride straight up and then drop straight down really fast are operated by strong magnets also and therefore, bad for pumps.
If you go to amusement parks, stick with roller coasters, ferris wheels, merry go rounds, and other activities....(or take your pump off...which i wouldn't recommend)
Have a fun summer!