What could a slight bulge 6 inches above my right outside ankle be? No pain, feels like a water pocket. Not right under my skin.

Cyst. Can be a cyst which is a fluid filled mass. Location plays an important part in the diagnosis. If necessary, the mass can be aspirated and the fluid sent for microscopic exam.
Normal anatomy. It is a perforation through the fascia of the lower leg through which passes the superficial peroneal nerve. In some folks this perforation can be slightly larger than others, allowing a slight bulge of tissue, mostly fatty tissue, to extend outward. Unless painful, no worries.
Evaluation. This should be evaluated by a specialist, through possible imaging such as x-ray or MRI depending on the nature of the findings.