To answer a suggestive question from DNOWS
Steve they are permitted. Did you expect something different?http://dailynews.openwaterswimming.com/2014/07/assisted-or-unassisted-marathon.html While this determination of assistance and unassistance is the determination and ultimate decision of the Marathon Swimmers Federation, the World Open Water Swimming Association looks at these questions through the dual perspectives of (a) history, and (b) safety.
But it will be interesting to see what and how the marathon swimming community will judge swims that permit buoys or poles or other equipment to help guide a swimmer through a potentially dangerous stretch of water.
We don't remove buoys in shipping lanes before a swim do we? Those poles and buoys you're talking of are in the same category.