Modular Subsurface Buoys, often simply called Subsea Buoys, are mainly used in Offshore Oil & Gas or Offshore Wind, two industries of high relevance in Norway, where we keep most of our subsurface modular buoyancy in Stock, in quantities rounding hundreds of pieces. Castle Hills can supply a virtually unlimited range of subsea buoyancy, due to the modularity of our equipment, ranging from just a few tons to over 25 tons mega buoys, and even higher.