I must be missing something...

[molybdenum]

I wanted to practice dive-bombing and went to the training arena to fuss around a bit on my own, but all the icons/bases/whatever they are that let you start at various altitudes are enemy colors, so I can't up from them. How do I make it work?

[ImADot]

Go to the O'Club and switch country to the one that owns those bases. You can switch countries in the TA as often as you want.

[molybdenum]

Thanks, Imadot, that worked. Much appreciated.