It is possible to start one. It is not a trivial procedure. Other possibilities are join the closest and work out the distance issues. It also depends on what you want to do for the Aux. If it is boating safety instruction for the public, distance may not be an issue. If you want to get underway, that is different. Another possibility is to form a detachment. You, and a few others, belong to a distant flotilla (mostly administratively IIRC), but can act relatively independently. Decide what you would like to do first. Download the Aux Manual and check these out.
How far are you talking?