Its about hour and half, but if going on the transfer coach usually takes longer as they have to drop everyone off at the hotels on the way bit of a pain, but who cares your in Turkey again.
You will find travel in Turkey very easy, just go to tour operator and book Marmaris trip or do as we do, just go into Fetheye and jump the bus no probs.

it is 65km and takes about an hour in a private transfer or longer by t/o coach depending on the amount of drop offs,this can take up to 21/2 hrs

Bus from bus station in Fethiye to Marmaris took 3 hrs exactly to get there, when we went 2 weeks ago. Cost was 20TL each way but we got it for 18TL, tickets valid for 1 month