This section contain photographs of the wrecks as they lie on the seabed. Many of these photographs have been taken many years ago and will therefore not necessarily provide a view of the wreck as it exists today. However, the deterioration of the wrecks through time provides the viewer with an interesting insight into how a metal or wooden vessel will deteriorate over the years due to the action of the salty seawater and the Scottish weather. Underwater photography in Scottish waters is often a difficult exercise making the clarity of photographs taken extremely variable. The effects of rain water run off, plankton blooms, darkness and sometimes pollution provide visibility that can be 30 metres plus on offshore wrecks to as little as one metre in some cases in the Firth of Clyde or Firth of Forth. The skill of the photographer and the use of sophisticated photographic equipment and lighting combine to produce the best possible views of the wreckage but often pure luck contributes the best possible shots. The final colourful complication comes from the often beautiful colourful sealife that often encrusts the man made reefs that the wrecka have become. The next section gives the viewer an idea of the typical types of sealife encountered on the wrecks.