This is getting out of topic................
Personally i dont get those 'G's that often. (turtle ride... ). i dont think you will get dizzy that easily except ur ride is near to fighter plane speed.
but again, you might have 'weaker' side for Gs.
So far i only have 2 type of dizziness. 1 caused by physical and another is from what my eyes see.
1st person shooter from computer game, your body is not moving while your eyes keep on looking at teh screen. i get dizzy from this kind of scenario.
2nd type is, your body is moving (well... i dont remember all the stuffs they thought in bio class anymore.) where we got sum sort of thing that make our body balance. riding roller coaster, getting seasick or driving ard twisted road will make sum ppl puke n dizzy.
if you know which type u get dizzy from, it will be much more easier for you to adjust yourself thru trainning.
but again, there are such thing if u get overly excited, u might feel dizzy and puke also. if this is the case, it is very easy to manage.