Year-roundOrange-spotted TrevallyFlavocaranx bajadSeen here
50%of dives
Boat dive · Big animals · Coral · Drift · Wall
Southwest Pinnacle
Southwest Pinnacle is a cluster of granite peaks rising from deep water roughly 7-10 km southwest of Koh Tao, reached by boat in about 45 minutes.
Also called Gong Tung Gu, Kong Hin Tong Ku, Kong Tong Ku, Secret Pinnacle, South West, South-West Pinnacle, סאות'ווסט פינקל, กองตุ้งกู, กองหินตุ้งกู, กองหินเซ้าท์เวสต์
- Depth
- 4-40 m
- Level
- Advanced
- Visibility
- 17–28 m
- Water
- 28–31 °C
- Entry
- Boat dive
The verdict
A good dive, worth a day.
Southwest Pinnacle is a cluster of granite peaks rising from deep water roughly 7-10 km southwest of Koh Tao, reached by boat in about 45 minutes. The rocks run from about 4-5 m at the shallowest tops down to around 30 m, with some reports reaching 40 m, and are covered in soft corals, sea fans and sponges.
Schools of barracuda, trevally and fusiliers circle the peaks, giant groupers hold close to the rock, and whale sharks turn up here at times. Currents can build, so the site is best suited to advanced divers with good air consumption.
Location
Map & nearby sites.
Interactive map loads here. Every site on it is also listed on this page.
Right now · updated 12 Nov 2026
November is a good month to dive.
November scores 7.5, against 7.6 in its best months. Live sea readings from NOAA Coral Reef Watch and NOAA WaveWatch III as of 10 Nov 2026.
Water29 °C+1.1° vs normalTick: normal for Nov, 28 °C
Visibility18 mtypical for NovPoor days 15 m · 1 day in 4 is worse
Waves1.2 mModerate6 s period
Reef stressNo stressNOAA Coral Reef Watch heat stress
When to go
Best Apr-Jul, Sep-Oct.
Every month gets its own Divegrade score from that month's marine life, visibility, reef and reviews. Across Koh Tao as a whole, the best months are Mar-May.
Divegrade score by monthPick a month for its full guide
Water temperatureSurfaceDive depth28–31 °C
VisibilityBad day to great dayTypical10–37 m
How is this measured?
Mostly from years of satellite readings of how clear the water is around this site. Each bar runs from a bad day, which about 1 day in 10 is worse than, to a great day, which about 1 day in 10 beats; the line marks a typical day. Satellites can't see through cloud, so stormy days are underrepresented and the real bad days can be murkier. For 12 months here, local dive centers report worse days than the satellites see, so the bar starts at their figure. Logged dives will sharpen it over time.
Chance of seeing it on a dive, by monthThe big draws first, then the most frequent. Share of sampled dive days that recorded the species. Months with few dives on record lean on the months around them and the rest of the year, and are shown lighter. A dash means under 1 %.
| Species | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Orange-spotted Trevally | 50 | 50 | 50 | 50 | 50 | 46 | 42 | 44 | 48 | 56 | 60 | 55 |
 Magnificent Sea Anemone | 67 | 67 | 67 | 67 | 67 | 70 | 72 | 67 | 58 | 61 | 70 | 70 |
 Scarlet-tailed Squirrel-fish | 50 | 50 | 50 | 50 | 50 | 46 | 42 | 44 | 48 | 56 | 60 | 55 |
 Java Rabbitfish | 50 | 50 | 50 | 50 | 50 | 55 | 58 | 56 | 52 | 44 | 40 | 46 |
 Indo-Pacific sergeant | 50 | 50 | 50 | 50 | 50 | 46 | 42 | 48 | 57 | 56 | 52 | 50 |
 Banded coral shrimp | 50 | 50 | 50 | 50 | 50 | 50 | 50 | 48 | 43 | 47 | 56 | 55 |
 Black Sun Coral | 50 | 50 | 50 | 50 | 50 | 50 | 50 | 48 | 48 | 53 | 52 | 50 |
 Chocolate Hind | 50 | 50 | 50 | 50 | 50 | 50 | 50 | 48 | 48 | 53 | 52 | 50 |
 Indo-Pacific Giant Barrel Sponge | 33 | 33 | 33 | 33 | 33 | 39 | 44 | 38 | 29 | 26 | 27 | 30 |
 Tiger cowrie | 33 | 33 | 33 | 33 | 33 | 39 | 44 | 38 | 29 | 26 | 27 | 30 |
 Wimple Fish | 33 | 33 | 33 | 33 | 33 | 39 | 44 | 38 | 29 | 26 | 27 | 30 |
 Bigeye snapper | 33 | 33 | 33 | 33 | 33 | 30 | 28 | 29 | 29 | 34 | 43 | 39 |
Marine life
Magnificent Sea Anemone on most dives.
4.4Big draws. A shark, ray, turtle or other big draw on about 5 dives in 10 in the best months, most often orange-spotted trevally.
6.6Reef life. Variety: how many different species a few dives here turn up, compared with other sites.
The big draws first (sharks, rays, turtles, octopus and the like) when they turn up on at least 1 dive in 20 in their best month, then the regulars, ranked by how often divers record them across the year. Each percentage is the share of sampled dive days that recorded the species. Where this site has few records of its own, sightings from similar nearby sites (same side of the island, similar depth and exposure) are added at a lower weight and marked "seen nearby".
Year-roundYear-roundMagnificent Sea AnemoneRadianthus magnificaSeen here
67%of dives
Anthozoa
Photo: (c) freefri_, some rights reserved (CC BY) · CC BY · taken elsewhere
Year-roundJava RabbitfishSiganus javusSeen here
50%of dives
Photo: jon hanson on flickr., via Wikimedia Commons · CC BY SA 2.0 · taken elsewhere
Year-roundIndo-Pacific sergeantAbudefduf vaigiensisSeen here
50%of dives
Photo: (c) portioid, some rights reserved (CC BY), uploaded by portioid · CC BY · taken elsewhere
Year-roundBlack Sun CoralTubastraea micranthusSeen here
50%of dives
Anthozoa
Photo: (c) desertnaturalist, some rights reserved (CC BY), uploaded by desertnaturalist · CC BY · taken elsewhere
Year-roundChocolate HindCephalopholis formosaSeen here
50%of dives
Photo: portioid, via Wikimedia Commons · CC BY SA 4.0 · taken elsewhere
Photos
4 photos. All from this site.
Divers pick the cover photo. Open any photo and vote for it; the one with the most votes leads this page.
Diver reviews
No reviews yet.
Verified dives count more.
Reviews linked to a logged dive, and reviews from experienced divers, carry more weight in the score.
- 2.5×
- a review backed by a logged dive here, vs. one that isn't
- 2×
- a review from a 100-dive diver, vs. a first-timer's
Dived Southwest Pinnacle?Sign up free to share how it went. Import your dive log and your review counts as verified.Share how it went. Divers with a logged dive here get the verified badge.
Nobody has reviewed Southwest Pinnacle yet. Be the first: reviews from divers with a logged dive here count most.
Dive centers
11 dive centers run Southwest Pinnacle.
Confirmed: each lists this site on its own website. Listed alphabetically.
| DIVE CENTER | AGENCIES | NITROX | CONTACT | Action |
|---|---|---|---|---|
Big Blue DivingKoh Tao | SSI | Not known | Website+66 77 456 123 | View |
Crystal DiveKoh Tao | SSI | Yes | Website | View |
Dive Poin Koh TaoKoh Tao | SSI | Yes | Website+66 77456231OSM | View |
Flow DiversKoh Tao | PADI | Yes | Website+66 82 679 2382OSMinfo@flowdivers.comOSM | View |
French Kiss Divers - ChalokKoh Tao | SSI | Yes | Website+66641276082frenchkissdivers@gmail.com | View |
Goodtime AdventuresKoh Tao | SSI | Yes | Website+66872753604OSM | View |
Hydronauts Diving ResortKoh Tao | RAID | Not known | Website+ 66 080 065 8782OSMinfo@hydronautsdiving.comOSM | View |
Nava Scuba DivingKoh Tao | PADI | Yes | Website+66 77 601198OSMinfo@navascuba.comOSM | View |
New Heaven Dive SchoolKoh Tao | SSI | Not known | Website+66 77 457 045info@newheavendiveschool.com | View |
Siam Scuba Dive CenterKoh Tao | BSAC, CMAS, NAUI, PADI, RAID, SSI | Not known | Websitesiamscubadivep@gmail.comOSM | View |
The Dearly Dive Koh TaoKoh Tao | PADI, RAID, SSI | Not known | Website+66-(0)77-332-494info@thedearlykohtaohostel.com | View |
Not confirmedTwo more centers likely dive here
These centers run trips to sites near Southwest Pinnacle or are based within 10 km, but their own websites don't name Southwest Pinnacle. Ask them before you book. Run trips here? Claim your listing and add it.
| DIVE CENTER · WHY LISTED | AGENCIES | NITROX | CONTACT | Action |
|---|---|---|---|---|
Ihasia Diving Koh TaoNot confirmed Based 9.6 km awayOSM | SSI | Yes | Websiteinfo@ihasiadivingkohtao.comOSM | View |
Pura Vida DivingNot confirmed Based 9.8 km awayOSM | Not listed | Not known | Websitepuravidachalok@gmail.comOSM | View |
OSM From OpenStreetMap (© OpenStreetMap contributors, ODbL), not from the center's own website.
Safety & rules
Know before you drop.
Depth, current and certification are safety calls. This isn't a dive briefing: your guide gives that on the boat or at the entry.
Hazards
No specific hazards recorded. That doesn't mean there are none: ask locally.
Rules and requirements
- Who can dive it
- Advanced Open Water (or equivalent), typically to 30 m. Koh Tao sites for Advanced Open Water divers
- Local rules
- No specific rules recorded.
- Park fee
- None known
- Depth limits
- The site goes past 30 m, the usual recreational limit. Plan your depth with your guide and set your computer's ppO₂ alarm if you dive nitrox.
- Sources
- Dive center websites, derived, NOAA Coral Reef Watch, NOAA WaveWatch III and web coords.
If a diver is hurt: oxygen first, then call for helpFor suspected decompression sickness give 100% oxygen right away and contact local emergency services. DAN emergency hotline: +1 919 684 9111. Check where the nearest recompression chamber is before you travel, and carry dive insurance with evacuation cover.
Questions
When is the best time to dive Southwest Pinnacle?
April, May, June, July, September, October score highest for Southwest Pinnacle.
What certification do you need for Southwest Pinnacle?
Advanced Open Water. Advanced Open Water (or equivalent), typically to 30 m. Depth 4-40 m.
How we grade
One number, built from dives people actually logged.
- Big draws or varietyMarine life scores the better of two things: how often sharks, rays, turtles and other big draws turn up, and how varied the reef life is, plus a little for having both. Both are per dive, so busy sites can't win on volume.
- By monthEvery month has its own score. Pick a month to see yours.
- Thin data, cautious scoreFew dives or reviews? The score leans toward the regional average.
- Graded as a pinnacleSouthwest Pinnacle is a deep, exposed offshore site, dived for the structure and the life it draws more than for coral. Marine life counts for 45% of the score here and the reef 10%.
- Reef healthThe reef score counts coral variety, and recent marine heatwaves that bleach coral take up to 3 points off it, fading over the years after as the reef recovers. Here: the 2024 marine heatwave (peak 8.3 °C-weeks of heat stress, when coral bleaching is likely), −0.9.
- Hard isn't worseCurrent and depth are shown on their own. A tough site can still score 10.
Sources for this page
Site facts: Dive center websites, derived, NOAA Coral Reef Watch, NOAA WaveWatch III and web coords. Occurrence data from GBIF.org; sea conditions from NOAA Coral Reef Watch and Copernicus Marine. Score computed 12 Nov 2026 from 6 logged dives and 0 reviews: low confidence.
Water temperature: average surface temperature by month from NOAA OISST climatology; at a typical dive depth here from the E.U. Copernicus Marine Service ocean reanalysis. Visibility: NASA satellite water-clarity data, local dive center reports and logged dives.
Photo credits
Herring Scad near Southwest Pinnacle: (c) portioid, some rights reserved (CC BY), via iNaturalist (CC BY). Slender Grouper near Southwest Pinnacle: (c) portioid, some rights reserved (CC BY), via iNaturalist (CC BY). Orange-spotted Trevally near Southwest Pinnacle: (c) portioid, some rights reserved (CC BY), via iNaturalist (CC BY). Scissor-tailed Fusilier near Southwest Pinnacle: (c) portioid, some rights reserved (CC BY), via iNaturalist (CC BY).