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 are distinct from submerged soils; the latter form in uplands but become submerged as a result of increased water tables, flooding events (such as those caused by Beaver Dams) or rising sea levels.