little word of advice... (and i know this from personal experience)
what they are looking for in your tests is someone that won't give up when the going gets tough. so when they ask you if you've had enough, even though you will probably be fecked from rolling out and rolling up hoses for the past half hour...say "no, i'm okay thanks" and carry one with the task in hand.
and if you don't get in first time, apply again. and again and again. A few (not many) recruit from outside their county so it's worth checking that out too as there is a lot of competition for jobs.
and get REALLY fit... competition is tough.
But above all GO FOR IT. don't get stuck in a rut or in a job that pays too well to leave even though you don't enjoy it.
All the best x