Overwatch Vortex and number of attacks

[twieb]

Do you need to have base attack +16 to fully use this feat? To make 4 readied attacks?

Overwatch Vortex
You are ready to respond to many more of your foes’ actions.
Prerequisites: Overwatch Style, Overwatch Tactician,
Precise Shot, Rapid Shot, Weapon Focus with the chosen
weapon, base attack bonus +11.
Benefit: While using the Overwatch Style, as a fullround
action you can ready up to four ranged attacks, each
with its own triggering event. You take a –2 penalty on
attack rolls made with these readied actions.

[Casual Viking]

Nope. Nothing in the feat suggests that you do. High BAB is a source of multiple attacks, not a cap. Besides, the prerequisites for the feat are "must be able to make four attacks".