REA - RAPID ENVIRONMENTAL ASSESSMENT (2003) A Rapid Environmental Assessment (REA) of this area was conducted in 2003. The intention of this REA was to locate unknown dangers quickly. The line spacing employed in the REA was wider than is considered necessary to fully disprove shoals, therefore previously charted shoals have had to be retained. As a consequence this chart shows a combination of both the 2003 REA data and any previously charted shoals. However, ED (Existence Doubtful) has been attributed to any previously charted shoal where the 2003 REA data shows no evidence that it exists. Within this area the position of the vast majority of data, including depths and buoys, will have been surveyed on WGS84. All previously charted shoals, however, will be on an unknown datum. To distinguish the two sets of data, the attribute PA (Position Approximate) has been added to those shoals on the unknown datum. They should therefore be easily identified.