You will have around 2 hours free time Olu Deniz and how you use this time is up to you.  If you don’t wish to go to the lagoon, Olu Deniz itself is a friendly seaside resort with plenty of shops, bars and restaurants.  You may have time to make a short visit to Hisaronu and even Fethiye but you are expected to be back in plenty of time for the next part of the excursion.  It is unfair to keep guests waiting for passengers who do not return on time.