How to read Komodo dive forecasts and reef-monitoring data

For divers in Komodo National Park, the safest way to interpret sea conditions is to read wave height and current forecasts together, then match them to the site and vessel plan. BMKG publishes separate marine forecasts for Labuan Bajo waters and the park, while park monitoring shows reef condition is assessed through repeated surveys rather than a single health score.

What does BMKG’s marine forecast measure?

BMKG’s Labuan Bajo waters forecast reports wind direction and speed, gusts, significant wave height, wave category and current direction and speed. The agency defines significant wave height as the average height of the highest one-third of waves during an observation period, a measure used for maritime safety and planning, according to BMKG’s Ocean Forecast System, 2026.

That means a forecast value is not a promise that every wave will have exactly the displayed height. It is a statistical description of sea state, so divers and crews must read it alongside wind, gusts, current and the intended route.

How are waves classified?

BMKG classifies waves from 1.25 to 2.5 metres as “moderate”, 2.5 to 4 metres as “high”, 4 to 6 metres as “very high” and above 6 metres as “extreme”, according to BMKG’s wave-warning page, 2026.

For the Labuan Bajo area, the forecast page also displays conditions for currents and waves separately. A calm harbour forecast therefore does not describe every exposed passage or dive site in Komodo National Park.

Why can conditions differ between Labuan Bajo and a dive site?

BMKG provides a forecast specifically for Labuan Bajo waters and separately identifies Komodo National Park waters in its warning products, according to BMKG, 2026. The relevant marine area depends on the vessel’s route, exposure and position, so a port reading should not be treated as a complete substitute for a site-area forecast.

Currents also matter independently of wave height. A relatively low wave category can still coincide with a current that affects entry, descent, drift and the vessel’s ability to remain positioned near divers.

How does the park measure reef health?

Komodo National Park’s monitoring programme surveys 185 reef sites every two years, according to the park’s Monitoring and Research page, 2026. Surveys use snorkelling at 4 metres and scuba diving at 8 metres and 12 metres, with observers recording estimated shares of live hard coral, dead hard coral, soft coral and other habitats.

The park’s published monitoring description says reef destruction appeared to stop from 1996 and that hard-coral cover then began a slow recovery of 2% per year. That historical figure describes the monitoring account’s reported trend, not a current condition for every reef or dive site.

What should a forecast briefing cover?

• Wave height and category for the route and site area.
• Wind speed, gusts and direction.
• Current direction and speed.
• The difference between harbour conditions and exposed park waters.
• The planned entry, drift and vessel-positioning method.

Sources

• BMKG
• Komodo National Park