It is not that far to visit Zoomarine I think it's about 20 to 30 mins away by taxi not sure of the cost of a taxi, we really enjoyed swiming with dolphins is a fantastic experiance, it might be a idea to book in advance as it can get booked up for info and prices check the lin below, we booked over the phone form the UK without any problem

http://www.zoomarine.com

Not sure about how far it is, but both my daughters swam withthe dolphins in August last year, they thought it was fantastic and a real highlight to the holiday. I would suggest you book in advance as you can then request your timeslot, Zoomarine is a lovely complex apart from the dolphins so you might want to spend some time in there if you have enough time a shore from the boat.