Could you ensure that anyone simulating the Nav radar role spends a good portion of their session bent over the rear view periscope (in a 2 hour tanker-tanker training slot that's a lot of bending.) Oh and of course they will have the parachute harness fully done up to increase the discomfort level.
This will ensure that they get disc problems which will last them the rest of their lives.
Well, I assume you want to give a realistic experience!