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China Walls / Portlock Wall

Hawaii - Oahu, United StatesDirections
Advanced suggested9–17 m (30–56 ft) depthBoth entry3mm wetsuit typical

China Walls / Portlock Wall at a glance

China Walls / Portlock Wall is an advanced both dive site in Hawaii - Oahu, United States with depths of 9–17 m (30–56 ft). Typically most favorable Oct · from 3 years of archive data. Divers commonly see Hawaiian green sea turtle, Frogfish, and Reef fish. Recent reports put the water around 27°C (80°F). Check the latest conditions and entry details before you go.

Favorable window now· until 18:00 · sunset 17:58

Forecast for this hour · 10:00 · run 15 h ago
1.1 m (3.6 ft)waves — about a meter expected (waves — about four feet expected)

Tap a factor for its source and model point · Forecast 27°C · seasonal avg 27°C ( · Forecast 80°F · seasonal avg 80°F)

Site hazards: Cliff entry/exit, surge, strong current, low entry visibility, fishing line/hooks, caves/nooks with no air pockets, overhead temptation, slippery rocks, and documented serious surface-condition risk.

Read the full hazards ↓

Dive windows this week

Lightest wind: Tue
Mon7:00–18:00 favorable

1.1 m waves · 7 kn wind (3.6 ft waves · 7 kn wind)

Tue7:00–18:00 favorable

1.2 m waves · 6 kn wind (3.8 ft waves · 6 kn wind)

Wed7:00–8:00 favorable, 8:00–10:00 moderate, 12:00–18:00 favorable

1.5 m waves · 7 kn wind (5.0 ft waves · 7 kn wind)

Thu7:00–10:00 favorable, 10:00–18:00 moderate

1.5 m waves · 11 kn wind (4.8 ft waves · 11 kn wind)

Fri7:00–18:00 moderate

1.4 m waves · 12 kn wind (4.7 ft waves · 12 kn wind)

Sat7:00–8:00 favorable, 8:00–9:00 moderate, 9:00–18:00 favorable

1.3 m waves · 8 kn wind (4.2 ft waves · 8 kn wind)

SunNot in the forecast yet

Favorable windowModerate window— no window

Every forecast dive window each day, site-local time, from wave and wind forecasts. Numbers under each bar are daylight averages.

First light 6:08 · Sunrise 6:31 · Sunset 17:58 · some windows run past sunset

Source: Open-Meteo marine · model point 3.4 km from site · updated 25 Oct, 19:23 GMT-10

Forecast only — always assess conditions on site.

Compare this weekend’s windows near China Walls / Portlock Wall

Forecast · NOAA tide model

Tide & slack timing

Loading tide predictions

Recent diver reports

Dated firsthand observations from divers — not current conditions.

No diver reports for this site yet. — one dated observation helps every diver after you.

Dived here today — did the forecast match?

What Divers Say

Best time: Only on flat or near-flat south/east-shore conditions; Oahu Dive Guide recommends less than about 2 ft waves for shore attempts.

Based on community reviews and site data. Conditions vary — always verify before diving.

Best months, historically

What conditions have historically been typical at this site, month by month — not a forecast.

  1. January, 5% of days have historically been favorable, water has typically been 25°C (77°F), waves have typically been 2.5 m (8.2 ft), wind has typically been 17 knots
  2. February, 4% of days have historically been favorable, water has typically been 24°C (76°F), waves have typically been 2.8 m (9.2 ft), wind has typically been 20 knots
  3. March, 12% of days have historically been favorable, water has typically been 24°C (76°F), waves have typically been 2.3 m (7.6 ft), wind has typically been 20 knots
  4. April, 7% of days have historically been favorable, water has typically been 24°C (76°F), waves have typically been 2.3 m (7.5 ft), wind has typically been 20 knots
  5. May, 5% of days have historically been favorable, water has typically been 25°C (77°F), waves have typically been 2.0 m (6.6 ft), wind has typically been 19 knots
  6. June, 13% of days have historically been favorable, water has typically been 26°C (78°F), waves have typically been 1.9 m (6.2 ft), wind has typically been 19 knots
  7. July, 10% of days have historically been favorable, water has typically been 26°C (79°F), waves have typically been 1.9 m (6.2 ft), wind has typically been 20 knots
  8. August, 14% of days have historically been favorable, water has typically been 26°C (80°F), waves have typically been 1.9 m (6.1 ft), wind has typically been 19 knots
  9. September, 12% of days have historically been favorable, water has typically been 27°C (80°F), waves have typically been 1.8 m (5.9 ft), wind has typically been 18 knots
  10. October, 19% of days have historically been favorable, water has typically been 27°C (80°F), waves have typically been 2.0 m (6.4 ft), wind has typically been 16 knots, historically most favorable
  11. November, 3% of days have historically been favorable, water has typically been 26°C (79°F), waves have typically been 2.5 m (8.3 ft), wind has typically been 19 knots
  12. December, 2% of days have historically been favorable, water has typically been 25°C (78°F), waves have typically been 2.6 m (8.5 ft), wind has typically been 18 knots

October has typically had the largest share of favorable days here. Conditions vary year to year — this is historical context, not a forecast.

Based on 3 years of archive data. Bar height shows the share of days each month whose conditions have historically scored favorably.

Marine life recorded at this site, by month

Recorded observations — evidence of past sightings, not a promise of what you’ll encounter.

Species seen here

Rough labels: “Commonly seen” usually means two or more recorded sightings near this site in public dive logs (GBIF), “Occasionally seen” one; “Seasonal” and “Rarely seen” come from dive-guide research. Not a measured rate.

  • Pelagic triggerfish recorded here Jan (1 record)

    Canthidermis maculatamost recent 2013

  • Sea eagle recorded here Jan (1 record)

    Myliobatis aquilamost recent 2013

Newest record here: 2013. Counts are occurrence records near this site from public biodiversity datasets (GBIF), grouped by calendar month across all sampled years. Sightings vary — past records are context, not a prediction.

Fills & rentals nearby

Facts from OpenStreetMap, corrected by the community — listed by distance only. Details change; confirm with the shop.

Shop facts come from OpenStreetMap and community corrections, shown nearest first. PickADive lists facts and contacts only — no listing is sponsored or ranked.

Data updated July 2026

Site details

Portlock/China Walls is a lava wall and cave/nook dive along Oahu's southeast shore. The underwater route follows the cliff wall past caves, arches, and mini-canyon features where turtles and whitetip reef sharks may rest. It is a rewarding dive only in very calm conditions and is safer by boat for many divers.

boatcaveshorewall

Cliff entry/exit, surge, strong current, low entry visibility, fishing line/hooks, caves/nooks with no air pockets, overhead temptation, slippery rocks, and documented serious surface-condition risk.

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