Abstract: A sport fishing outrigger assembly with a position adjustment positive locking mechanism capable of indexable adjustment and nonslip positive locking of a rotatably deployable outrigger boom assembly. The mechanism uses a fixably attached (yet replaceable) non-metal split collar with a plurality of castellated, vertically oriented indexing aperture slots. The slots receivable engage a metal locking bar as attached to a handle assembly, the assembly being mounted for pivotal, downward penetration of the bar with the aperture slots. The rotatable boom assembly is further isolated from an containing indexing pipe by a plastic bushing at the top and a plastic bearing at the bottom to prevent metal-on-metal rotation of the wearable parts.