Thank you for your reply. Yep my children and I have Oz passports.
I realise the exhange rate can vary considerable, I just wondered if it would be too optimistic on today's rates to expect to live as well as we could here on his pension. I am making a leap of faith that the exchange rate from our perspective won't be hugely worse in the future.
We're not looking for an improved standard of living in terms of what we can afford but we don't want to be struggling to live in a similar way as we would in the UK (near a beach, fairly comfortable, enjoying several sports). The climate and lifestyle will compensate for much.