The Myth That You Need Great Visibility
A few days before Christmas, Members of the Subic Bay Dive Association got together for a dinner. The dinner guest included the owners of some of the dive centers along with their instructors and dive masters. After dinner, the conversations focused around diving and the local dive industry. One point that was fully agreed with was that almost all the complaints divers make about diving in Subic concerned the unpredictable visibility. That lead the discussion around to the question how important is visibility?
How important is visibility?
This first point is that visibility is a bit relative. I have been diving in the Caribbean where dive leaders are apologizing for bad visibility when it drops to 20 meters. Some of the divemasters from the U.K., pointed out that in many dive sites off the coast of England or in the North Sea, visibility of 2 meters would be considered great. The important question becomes, at what point does the limit of the visibility impact the quality or safety of the dive. This mostly relates to the individual divers experiences and skills. While divers who have never dived in limited visibility may feel uncomfortable at first, there is always an in-water guide to help so it is safe to say that safety is not compromised. We seldom hear divers who have completed either the SSI limited visibility certification or the PADI night diving course complain about visibility. This is because they have come to accept that limited visibility does not lead to a bad diving experience.
There are really only two dive sites, the USS New York and the concrete wreck, where visibility can become poor enough to consider aborting a dive. It does not happen often but does occur. The USS New York, sits on the edge of the shipping channel within the Port area. Passing ships can stir up the silt that then floats over the wreck, one ship is generally not a problem but a few over a short time period might be. The concrete wreck sits near the mouth of the largest river running into the bay. Run offs are carried by this river and on to the wreck. Due to its depth, possibility of poor visibility and the fact that the wreck is being buried in silt, this wreck is our least dived wreck.
Second, the visibility of Subic Bay varies. The closer the dive site is to the opening to the South Philippine Sea, the better the visibility generally is. The Barges, San Quentin, Runway Reef and the Canyons generally have pretty fair visibility. Even on wrecks with decreased visibility the conditions can change between the surface interval between back to back dives, better or worst. On an average day, you still can expect 5 to 10 meters on the worst sites.
A third point to consider are the wrecks themselves. The range of wrecks we have makes diving Subic Bay worthwhile even with the more limited visibility.
That leads us back to the question of what is acceptable for the individual diver. The largest impact caused by limited visibility is that it reduces the light that reaches the diver, so what the dive does see seems gloomy. The diver has to concentrate harder to see what is around them. Experienced divers who are interested in a wreck often concentrate on just a small portion of the wreck at a time. They generally are comfortable with the visibility as long it is within range of their dive buddy. Wreck certified divers doing penetration dives are prepared and comfortable with low visibility, inside a wreck low visibility is common and your field of view is limited by your dive light in most cases.
It is a terrible name for a specialty of diving that is becoming very popular. In the purest sense of the title, muck
diving is done on sites with a base of black volcanic sand. It is said that two divers on a liveaboard in PNG, decided to check out an area were the liveaboard and anchored for lunch. The dive leader told them it was a waste of time nothing was there. They dove down an saw a barren black sand bottom. However, on a closer examination they found many small species that were hiding in the sand. This black sand was very very fine allowing animals a easy time to bury themselves and it is also easy to disturb it creating conditions of very limited visibility.
The term muck diving has expanded and includes any dive site where the strata is bear of marine growth and easily disturbed. You are looking for the small harder to see marine life. A couple of years ago Sport Diver Magazine listed the best dive sites in Indonesia. High on the list was Ambon Island and its polluted murky waters.
Before the 1991 eruption of Mount Pinatubo, Subic Bay had crystal clear waters, healthy abundant coral and marine life, even shark nets across the beaches. The eruption left a meter of ash over much of Olongapo much of which eventually washed into the bay. Pockets of fine ash accumulated in places. These locations and others make for fine muck diving.
Subic Bay- the Low Visibility Diving Capital of the Philippines
One member of the dinner groups jokingly suggested calling Subic Bay the “Low Visibility Diving Capital of the Philippines”. While it does lack marketing potential, it is an accurate statement. If a diver judges a dive location solely on the visibility, then they will not appreciate Subic Bay. If you are a diver that does not care what is 30 meters away but are concern about what is within the few meters around you, than Subic Bay may be perfect for you. Wreck diving, even external dives, does not need unlimited visibility. Muck diving conditions are best in low visibility. If the sometimes poor visibility at Subic Bay causes you concern, then make a reservation and take a night dive course.