When divers encounter the “Red Tide” in Tunku Abdul Rahman Park waters their immediate reaction is understandably usually disappointment due to the reduced visibility however dives can be fascinating in this natural phenomena.

As a British diver I am no stranger to cooler low viz dives which are somewhat testing at times however I have to say the red tides can often be a spectacular natural sight and a very interesting dive which I do enjoy. Sharp lines/edges where alga converge with clear waters can create breathtaking formations which resemble the dramatic thunder clouds seen in our skies. Passing between these layers can be great fun for the diver.

Occurring intermittently during the cooler water period of late February to early April in TARP and the local surrounding areas. The Red Tide is a seasonal algal (phytoplankton) bloom which can appear a deep and sometimes very dark rusty red or green colour. Sometimes manifesting into thick layers or huge clouds drifting in the shallow water column which can reduce visibility underwater to just a few inches in some severe cases however on the outer edges the waters can still be blue & clear.


Not all algal blooms are so dense and will usually just turn the waters a little cloudy but visibility will still be reasonable when diving, they are also harmless to divers (unless consumed) other than the obvious challenges of diving in low viz conditions.

Some intense red tides can however be harmful to certain coastal marine life such as fish, birds and marine mammals due to toxins that some species of alga may produce and the low oxygen content present in the water.

In some areas local authorities may recommend that fresh seafood should not be consumed by humans during the height of these blooms (check government guidelines in your local area).

Ultimately diving in challenging conditions can be fun in moderation particularly if we can appreciate the seasonal wonders of our amazing underwater water world but if you do wish to dive in these more “extreme” environments basic care should be taken.

  • Be well informed, briefed and guided by your local dive professional.
  • Mentally prepare for the conditions.
  • Plan your dive and dive your plan.
  • Stay very close to your your buddy and move slowly.
  • Enjoy the experience of nature.