25-1. Ensure all WDZ parachute jumps are conducted using the following items and within the following conditions for all services: Daylight: warm weather conditions. (The Navy conducts day and night water parachute operations.). Ensure: Surface winds do not exceed 17 knots. The WDZ is not in or near the surf zone. Sea state is no more than 2. Sea state 2 indicates that wave height does not exceed 20 inches, as measured from a wave crest and the preceding trough. (Refer to MCRP 2-10A.6 or JP 4-01.6 for more information.) Water should be more than 10-feet-deep with no underwater obstacles at that same depth. Nighttime: All jumpers and equipment have chemical lights and strobes attached for night jumps. Night vision devices are used on the WDZ for all night drops.26-2. The drop zone safety officer guarantees: Drop control visual marking system consists of mirror, smoke, and VS-17 panels. Release method is CARP or VIRS. Helicopter or fixed-wing aircraft flying under visual flight conditions. Only one to three jumpers for each recovery boat for each pass. (U.S. Navy operations have one boat for five jumpers.) Boat-to-jumper ratio depends on unit and jumper experience with water jumps. One boat to one jumper is strongly recommended for units that rarely conduct WDZ operations. Sufficient boats are properly manned with the engines running during all live passes. “CLEAR TO DROP” is by radio or by all the boats driving in one big circle or boats arranged in another agreed upon configuration. “ABORT THE PASS” is by radio or by all the boats being scrambled or boats arranged in another agreed upon configuration. All combat equipment is waterproofed and float-checked. All floatation devices are approved, serviceable, and properly maintained.27-3. The Airborne commander is responsible for: All personnel scheduled for a water jump are not less than a Class 3 basic water survival swimmer qualified in compliance with TC 21-21, (U.S. Marine Corps combat water survival-1, U.S. Navy second class swimmer, qualified SEAL, special warfare combatant-craft crewman [SWCC], EOD, or U.S. Navy diver). All jumpers and safety swimmers have completed wet silk training within the past six months (12 months for U.S. Navy personnel). All equipment has been waterproofed and float-checked. All jumpers are using approved serviceable floatation devices. All jumpers have completed the required prejump training.