Hello Ed,
Sounds like a real pain! I just never get dizzy and what is more, I don't get seasick (useful if you sail in rough conditions!). I thought that PJ's idea of watching the plane to the exclusion of all else would help, but I presume that you have tried that.
I think that dizziness and sea/travel sickness may have the same physical basis, all down to the inner ear. As an experiment, you could try taking a travel sickness pill. Mind you most of them tell you not to operate machinery after taking one! So if you do give it a try, make sure that you have someone to start your engine for you. I don't want to finish up being sued if you get your finger in the prop!
Regards,
Andrew.