Image of seamarker in use

When used with standard dye, the NRL-developed surface film spontaneously spreads over the sea surface, making a much larger mark than the dye alone. The marked area is clearly visible in this photograph. These seamarkers have found use in search and rescue operations.

NRL research demonstrated that the one-molecule-thick films on water were readily detectable, both visually and by radar, with radar providing nighttime and poor weather detectability. The films were useful as seamarkers because the films dampen wave action over a wide area of water surface, thereby producing a highly visible artificial sea slick under a variety of environmental conditions. W.D. Garrett and W.R. Barger patented this invention as a chemical sea surface marker in 1972. In developing this product, they made comparative studies with the standard Navy dye marker. When the sea slick and dye were used in combination, the detectability of the resulting marker was greater than that of either component used alone. This is because the dye-only marker is barely visible at certain angles of viewing where the NRL-developed marker slick is obvious. At certain other angles, where the NRL slick was difficult to see, the dye stripe could easily be observed.