During his highly decorated naval career, Rear Admiral Dissanayake served on many ships and in various establishments and imparted his experience and knowledge for the progress of the navy.

Dissanayake enlisted in the Sri Lanka Navy as an Officer Cadet in its 11th Intake on 15 November 1982, undergoing basic training at Naval and Maritime Academy, Trincomalee.

He commanded the SLN flagship SLNS Sayura from 2006 to 2007, where 2 LTTE floating arsenal ships were hunted down and destroyed during the Sri Lankan Civil War.

[4] He also held the Flag officer commanding the naval fleet position based at Trincomalee during the Sri Lankan Civil War.

Other key staff appointments he has held at various times include:[5] In order of precedence: Badges & Pins