
Mona Island
Puerto Rico · United States
Mona Island is Puerto Rico's most remote and pristine diving destination, sitting 70 km west of the mainland in the Mona Passage with oceanic visibility routinely exceeding 40 metres. The island's protected marine reserve status means dense populations of Caribbean reef sharks, nurse sharks, and hawksbill sea turtles patrol walls that plunge from the limestone plateau into the blue. Strong currents funnel nutrients past the reef, supporting enormous schools of horse-eye jacks and a resident population of giant manta rays during summer months.
Conditions
Depth
5 to 50 m
Advanced depths
Current
Can be moderate
Can pick up on the edge
Visibility
25 to 40 m
Clearest in the calm season
Water
25 to 31°C
swimsuit or 1mm
Month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 26 | 25 | 26 | 27 | 28 | 28 | 29 | 29 | 29 | 28 | 27 | 26 |
| Vis (m) | 25 | 25 | 30 | 30 | 30 | 25 | 25 | 20 | 20 | 20 | 25 | 25 |
| Current | Moderate | Moderate | Gentle | Gentle | Gentle | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
Your chances of seeing each animal
Hawksbill Sea Turtle
Last confirmed Oct 9, 2025 · 2 records
Likely
About 6 in 10 dives
Mona Anole
Last confirmed Oct 23, 2025 · 4 records
Sometimes
About 1 in 3 dives
Caribbean Land Hermit Crab
Last confirmed Oct 5, 2025 · 1 records
Sometimes
About 1 in 3 dives
Yellow-Shouldered Blackbird
Last confirmed May 14, 2025 · 5 records
Sometimes
About 1 in 3 dives
Caribbean Bluehead Wrasse
Last confirmed May 12, 2025 · 2 records
Rare
Now and then
Caribbean Reef Shark
Expected
Known here, not yet in recent logs
Horse-eye Jack
Expected
Known here, not yet in recent logs
Giant Manta Ray
Expected
Known here, not yet in recent logs
Gear