Being 'significant' myself, the best option I can say is try it and see. Scooby is not friendly to tall people (legs become an issue,)or larger people so if there is a long queue, come back later, or ask the op on the door if you can jump ahead, see if you fit and then re-join the queue. At dreamworld be wary of wipeout the last time i went on it i burst a small blood vessel in my eye. The first time I went on it 8 times with no problems, a few years and a few kilos later a different story. The plane ride at dreamworld (no idea what it is called at the moment...) some of the planes are slightly bigger than others... aim for the back row... I had a few issues getting in that row, but i got on... the middle row was not possible. I sincerely hope he comes across and you both have a great time