The difference between subaqueous and submerged soils is that submerged soils formed in an upland environment then became submerged as a result of rising water tables, flooding events (such as a Beaver Dam), or sea level rise.
Subaqueous soils differ from submerged soils; the latter form in uplands but become submerged because of rising water tables, flooding incidents (such as those caused by Beaver Dams) or sea-level increases.