English

Noun

propwash deflection unit ‎(plural propwash deflection units)

1. A device that is placed over or behind the propeller of a boat to deflect the vessel's propwash downward. The result is a very effective form of agitation dredging. PDUs are primarily used by salvors to remove mud or sand from shallow water shipwrecks.

Synonyms

• deflector
• PDU

References

• http://www.fknms.nos.noaa.gov/regs/fmp2.pdf
• http://www.shipwrecks.com/ethics_in_underwater_archaeology.htm