An outrigger assembly for a fishing vessel to extend fishing lines away from the vessel, including a telescopic boom having a plurality of aligned `D` tubes of consecutively smaller diameters that can be individually locked in place when extended and having the smaller tubes telescopically mounted inside larger tubes for storage, first embodiment provides a manually operable locking mechanism using an external shift bullet to lock the tubes in place, and second embodiment combines the locking means of the first embodiment with a cam lever operated eyelet locking system, the eyelets provide support for a fishing rigging, both embodiments protect the locking mechanism from elements found in the environment.