The idea would be, roughly speaking, as follows:
- 9am– depart to Isla Grande (hang for 2 hours to swim/snorkel/sunbathe)
- 11:30am– sail towards Cholón (2 hours to party and chill)
- 2pm– sail to Playa Azul (90mins to hang)
- 3:30pm– sail back to Cartagena
Based on my research, I think we should rent these two boats, with each assuming a max capacity of 10-14 people so we can be comfortable: