Lieutenant Commander Knapp enlisted in the Navy on 5 March 1985, attending recruit training at the Recruit Training Center, Orlando, FL.
His first assignment was at Amphibious Construction Battalion TWO with a deployment to Honduras on the USS Harlan County (LST-1196) as a Crewmember and Project Supervisor. He transferred to Naval Construction Training Center, Gulfport, MS, in 1988, where he served as an A School Instructor and an A School Company Commander. In 1991, he reported to Naval Security Group Activity, Galeta Island, Panama. While in Panama, he served as the Antenna Shop Supervisor, maintaining 160 high/low ban antennas. In 1993, he transferred to Naval Mobile Construction Battalion ONE in Gulfport, MS, where he was assigned to the Air Detachment as Assistant Officer in Charge and Quality Control Manager. He was promoted to Steelworker Chief Petty Officer in 1995 while deployed to Rota, Spain.
In 1995, LCDR Knapp was assigned to Navy Recruiting District, Dallas, TX, as Recruiter in Charge. The District was named number two and number one in the Nation during his tenure of back-to-back years. In 1998, he reported to Amphibious Construction Battalion TWO as the Charlie Company Operations Chief. In September 1999, he was selected for the Chief Warrant Officer Program, commissioned as a Chief Warrant Officer 2 and then transferred back to Naval Construction Training Center, Gulfport, MS, for a second tour. During this tour of duty, he was the Charlie Company Commander and then the S4/Logistics Officer. In 2001, he received orders back to Amphibious Construction Battalion TWO. During his tour, he was the Assistant Training Officer and Force Protection Officer and was also responsible for all Officer Seabee Combat Warfare training and boards. He then made a deployment to the Kuwait Naval Base in support of Operation Iraqi Freedom and was the Officer in Charge for the Elevated Causeway System-Modular.
He was promoted to Lieutenant Junior Grade in October 2002 and promoted to Lieutenant in October 2004; he then reported aboard Construction Battalion Unit FOUR TWO THREE as the Officer in Charge. In October 2004, Construction Battalion Unit FOUR TWO THREE was disestablished and he served as the Executive Officer for the transition to Construction Battalion Maintenance Unit TWO ZERO TWO. In 2006, he was assigned to Center for Seabees and Facilities Engineering Detachment, Fort Leonard Wood, MO, as the Officer in Charge.
In June 2010, he reported to Naval Construction Training Center Gulfport, where he served as the Executive Officer; in October 2010, he was promoted to Lieutenant Commander.
Lieutenant Commander Knapp is Seabee Combat Warfare qualified and has earned an Associates of Applied Science (AAS) in business from Columbia Southern University. His personal awards include the Navy and Marine Corps Commendation Medal (five awards), Navy and Marine Corps Achievement Medal (six awards), Navy Unit Commendation Medal (two awards), the Battle E Ribbon, Good Conduct Medal (four awards), National Defense Service Medal (two awards), Sea Service Deployment Ribbon (three awards), Overseas Service Ribbon (two awards), Global War On Terrorism Expeditionary Medal, Global War on Terrorism Service Medal, Recruiting Excellence Ribbon, Expert Rifle Medal, and Expert Pistol Medal.