We will post a full review of the hotel within the next few days. However, we wanted to make this information public as soon as possible (have not seen any mention of this development in any other posts).
We have just returned from two weeks at GBP Tulum section and were surprised by the significant construction project underway beside La Gran Tortuga. Since we stayed in building 22, which is directly beside La Gran Tortuga, we were curious about the construction. We asked a total of 7 staff members to ensure we received a consistent and accurate response - aquatics staff (2), front desk / reception staff (2), customer service staff (3) - all reported the same information: GBP is building a dolphinarium which will open some time next year (final date not confirmed).
We have pictures which show grading equipment and a large boring machine. Activity was fairly constant each day and one aquatics staff member reported they are working hard to finish it. His comment about the hotel having concerns about reaction from the public and groups such as Green Peace seemed to ring true - security guards are posted at the construction site 24 hours a day.
Rooms blocks 23, 24, 25 and 30, 31 and 32 were unoccupied and some seemed to be undergoing renovation (i.e., painting).
The decision to install a dolphinarium - keeping dolphins in captivity for purposes of entertainment - seems to be contrary to the image GBP tries to convey related to eco-tourism ("eco-Bahia") and wildlife preservation practices, particularly related to turtles. It's a deal-breaker for us - we can't support any company that would make this kind of decision and we won't be returning.