MANILA, Philippines Aug. 19 (NNN-PNA) -- Four ships of the Philippine Navy are now taking part in the ongoing search-and-rescue operations for Department of Interior and Local Government Secretary Jesse Robredo and two civilian pilots who went missing after their plane went down in the waters off Masbate Saturday.
These are BRP Hilario Ruiz (PG-378), BRP Simeon Castro (PG-374), BRP Carlos Albert (PG-375), and DF-339.
One Islander aircraft is also supporting the search operations of the above-mentioned ships together with two diving teams with deep sea equipment.
As this developed, Department of Transportation and Communications Secretary Manuel A. Roxas II said that the depth of the search area is around 40 to 87 meters.
"Search area has depth of 40 to 87 meters. Human scuba can only do 10 minutes at 40 meters before nitrogen narcosis," he tweeted.
Nitrogen narcosis is a reversible alteration in consciousness that occurs while diving at depth.
It produces a state similar to alcohol intoxication or nitrous oxide inhalation, and can occur during shallow dives, but usually does not become noticeable until greater depths beyond 30 meters. -- NNN-PNA