Do you mean the amount of time that the dugong would spend in the tank being transported? It would depend on a number of factors, including where the dugong is picked up from and transported to, the capacity of the facility to accept it as soon as possible, among other unexpected occurrences. Variability of the time that it takes should be something which is accounted for in your design – how long can you ensure that the dugong will be safely transported? What design choices can you make to your tank to adjust to this uncertainty?
We have a Big Tricky Questions document (which you can find in our Resources section) which can help guide you when designing with variables and uncertainties.
I hope this helps, please let me know if you have any further questions!