If you book an excursion through the cruise planner, you are guaranteed to be back at the boat before the boat leaves, correct?! I`m looking at 1 excursion that only gives us 45 min from when its done until the boat leaves at 7 pm. I just want to make sure that we are absolutely guaranteed through the RC site excursions to be back at the boat in time?? Thanks! This will be our first cruise, so I`m unsure about some of this ?