Dolphin Swim Time to make it back to boat?

[Madshoes]

I booked Dolphin Swim through Dolphin Encounters on Blue Lagoon island independently.
The Dolphin swim is at 10:30am.

I did not book it through the Disney Cruise because it was sold out already.

We have to be back on the ship by 5:15. Anybody have this experience? Was it stressful to get transportation and or get back to the boat on time? We are going May 2017.

Questions
regular taxi to Paradise Island cost?
Time it took to get off the boat and find a Taxi?
Time it took to do swim and be ready for boat back to paradise island?

Any info would be greatly appreciated!