Puerto Rico Dive Sites

West Coast · Mayagüez

Tourmaline Reef

Also known as: Arrecife de Tourmaline · El Tourmaline · Tourmarine · Tourmaline Bank · Tourmaline · Tourmaline 10m · Tourmaline 20m · Tourmaline 30m · Tourmarine Reef

Depth
33–98 ft (10–30 m)
Access
Boat dive
Type
Spur & groove / canyons
Confidence
Moderate confidence

Overview

Tourmaline Reef is a shelf-edge spur-and-groove reef in outer Mayagüez Bay, about 7.5 nautical miles from Mayagüez, dived by boat at roughly 33 to 98 feet. A monitoring report called it one of the island's most diverse coral communities, though coral cover reportedly fell from about 60% in 2003 to 40% in 2009. It is a DRNA natural reserve; federal rules ban all fishing in its federal-waters portion from December through February and some gear year-round to protect red hind spawning. Check current rules.[1][2][3][4][5][6][7]

Site characteristics

  • Spur & groove / canyons[1]

Habitat & marine life

  • transects laid along successive spurs at 10–12 m, 18–21 m and 27–30 m[2]
  • Spur & Groove (Outer-Shelf) at station 'Tourmaline 10m'[3]
  • Spur & Groove (Outer-Shelf) at station 'Tourmaline 20m'[3]
  • Spur & Groove (Outer-Shelf) at station 'Tourmaline 30m'[3]

Marine life is what sources report having seen or commonly seeing — not a guarantee.

Access

  • Boat dive[5]
  • Federal rule: all fishing prohibited 1 Dec–end Feb in EEZ portion; pots, traps, bottom longlines, gillnets and trammel nets banned year-round (red hind spawning aggregation area)[6]

Safety considerations

No site-specific hazards are recorded in our sources. That does not mean there are none.

Ocean conditions change daily. Dive within your training, plan with current local information and consider a local professional guide. Full safety note.

Protected area

  • Arrecifes de Tourmaline Natural Reserve (Reserva Natural Arrecifes de Tourmaline)

    Natural Reserve · Puerto Rico Department of Natural and Environmental Resources · Site position falls inside the official boundary[7]

    NOAA's MPA Inventory classifies this area's protection level as "Zoned w/No Take Areas"; fishing: commercial fishing restricted. Anchoring: unrestricted.[7]

Regulations change. Check with DRNA (Departamento de Recursos Naturales y Ambientales) before diving.

Depth reports by source

ReportedSourceStatus
33–98 ft (10–30 m)García-Sais JR et al. (Reef Surveys) for DRNA/NOAA[1]Current source
to 36 ft (11 m)Puerto Rico DRNA Marine Resources Division[8]Current source
50–90 ft (15–27 m)Colleen Ryan & Brian Savage / Complete Dive Guide Publications[9]Historical (1998)

Historical record

What a historical source reported at the time. Not verified as current — access, moorings, reef condition and names may have changed.

Listed as “Tourmarine Reef (buoy 8)” · 50–90 ft (15–27 m) · 1998[9]

  • boat
  • north and east of buoy 8: many caves, some 30+ ft long
  • rock and coral with sand forming slopes and, in places, steep walls

Sources & verification

Last researched: 2026-10-04 · Last independently verified: not yet field-verified · Confidence: Moderate confidence

  1. 1.Monitoring of Coral Reef Communities at Isla Desecheo, Rincón, Mayagüez Bay, Guánica, Ponce and Isla Caja de Muertos, Puerto Rico, 2005 (Final Report) — García-Sais JR et al. (Reef Surveys) for DRNA/NOAA (2005-12) · Government dataset · Tier 1: Primary / authoritative · accessed 2026-09-25
  2. 2.Monitoring of Coral Reef Communities from Natural Reserves in Puerto Rico: Isla Desecheo, Isla de Mona, Rincón, Guánica, Ponce, Caja de Muerto and Mayagüez, 2007-2008 (García-Sais et al.) — Puerto Rico DRNA / NOAA (Reef Surveys) (2008) · Scientific publication · Tier 1: Primary / authoritative · accessed 2026-09-25
  3. 3.Puerto Rico Long-Term Coral Reef Monitoring Program Database Compilation (DwC-A v1.9, GBIF dataset b3b7d5c4-f73a-475b-a203-c6a1ddd040cd, DOI 10.15468/heuugg) — DRNA Puerto Rico / NOAA CRCP (published via OBIS-USA IPT) (2022-02-13) · Government dataset · Tier 1: Primary / authoritative · accessed 2026-09-25
  4. 4.Tourmaline Reef — Wikipedia · Other · Tier 3: Corroborating · accessed 2026-09-25
  5. 5.Puntos de Buceo / Dive Sites — The Dive Shop Puerto Rico (Mayagüez) (2011) · Dive operator · Tier 2: Specialist · accessed 2026-09-25
  6. 6.50 CFR 622.439 - Area and seasonal closures (EEZ around Puerto Rico) — U.S. eCFR / NOAA Fisheries · Government · Tier 1: Primary / authoritative · accessed 2026-09-25
  7. 7.NOAA Marine Protected Areas Inventory 2024 (feature service NOAA_MPA_Inventory_2023), State = PR — NOAA NOS Office of National Marine Sanctuaries - MPA Center (2024) · Government dataset · Tier 1: Primary / authoritative · accessed 2026-09-25
  8. 8.Puerto Rico DRNA Coral Reef Monitoring Project Report 2002 - Task 1: Monitoring of Natural Reserve Baseline Sites (M. Nemeth) — Puerto Rico DRNA Marine Resources Division (2002) · Government dataset · Tier 1: Primary / authoritative · accessed 2026-09-25
  9. 9.The Complete Diving Guide: The Caribbean, Volume 3 (Puerto Rico, US Virgin Islands, British Virgin Islands) — Colleen Ryan & Brian Savage / Complete Dive Guide Publications (1998) · Historical guide · Tier 3: Corroborating · historical
  10. 10.Final Report Puerto Rico Coral Reef Monitoring Program: 2025 Survey (Garcia-Sais, Williams, Sabater-Clavell, Carlo) — Reef Research, Inc. for DRNA (NOAA CRCP NA23NOS4820135) (2025-09) · Scientific publication · Tier 1: Primary / authoritative · accessed 2026-09-25

Facts are summarised in our own words from the sources above; we do not reproduce operators’ or publishers’ descriptions. How confidence is assigned.