Ocean Surface Water Sampling Devices.

This report traces the development and sea tests of various devices to obtain a surface water sample. The first were 1-liter polyethylene wash bottles with intake attachments. They were squeezed to create a partial vacuum and thrown from helicopters. In practice they collected over 100 milliliters of water. Other samplers were built around 1-liter filter flasks. These samplers were evacuated and parachuted to the water, where the impact would break open intake tubes. They were effective about 75 of the time in collecting a liter of water from 6 to 8 inches below the surface. Another sampler, also parachuted, captures a volume of the water surface by a cookie cutter action and drew it into a 1-liter Thermos bottle for protection from temperature change and sunlight. Filter paper bands gave way on becoming wet and released spring clips on rubber intake tubes. These samplers were only 60 effective in landing upright on the water. Faster Dewar samplers without the cookie cutter action but with the same intake method proved about 95 effective in collecting their combined capacity. A more elaborate sampler, having an electric timer mechanism to open spring clips and manually placed on the water, proved only about 60 effective because of unreliability of the mechanism. For larger volumes of water, a 5-gallon polyethylene carboy with a wooden board float on its neck to maintain the necessary filling orientation proved 98 effective. Author