Contact sheet containing 6 images. ENVELOPE TEXT:  Vietnam - C - weather - Monsoon & flood.  NOTES ON CONTACT SHEET:  Dan Derby, c/o JUSPAO Press Mission, APO San Francisco 96243 - Special to Overseas Weekly - Extended Photo Caption Vinh Long Flood Pictures - MONSOON MADNESS has struck at Vinh Long Airbase in the northern delta.  Someone didn't take into account the rains when a floating dredge went to work and fouled up the drainage pattern on the base.  Now offices and hootches are under six to twelve inches of water.  "This never happened before they started messing around with that dredge," said one trooper.  Another resident described the base as a floating cesspool, explaining that the latrines were under water.  "It's like sleeping in a septic tank."  One chopper pilot convalescing from a back injury told this story:  "I managed to get the stench of the water down by spraying the hootch with disinfectant and got my mind off of the mess by turning on the TV, then a damned frog hopped up on my leg.  I grabbed my crutches and sloshed over to the airfield headquarters and told the sergeant major that if that dredge was operating in the morning I'd get my old chopper and sink it!"  The waters are receding.