UPDATE (4:21 p.m.)—Local emergency crews are searching for a missing 21-year-old male boater in the Aberdeen Proving Ground area of the northern Chesapeake Bay.

At about 1:30 p.m., a 35-foot power boat carrying four people stopped about a mile west of Hail Point in Kent County, so they could go swimming. A 21-year-old male jumped feet first into the water, but did not return to the surface, according to Sgt. Art. Windemuth of the Maryland Department of Natural Resources.

The victim's name is currently being withheld, Windemuth said.

Multiple agencies, including crews from Aberdeen Proving Ground, Maryland State Police, Kent County, Harford County, Department of Natural Resources Police and the Susquehanna Hose Company responded, APG spokeswoman Karen Jolley and Susquehanna Hose Company Chief Scott Hurst confirmed to Patch.

Hurst said as of 3:15 p.m. that two boats from the Susquehanna Hose Company were on the scene, but had not found a boater.

Monday is the one-year anniversary of a drowning in the lower Susquehanna River. Michael Sawyer, 16, drown when swimming with friends on May 28, 2011.

Stay with Patch for updates.