swim platform grab rail - what diameter?

[seaman-recruit]

So sitting here in the Detroit rain (once again) and thinking about getting a Magma kettle grill on order from Defender. (The original size is on sale for $137.00 - http://www.defender.com/product.jsp?...6219&id=930353) I thought about the various mounts available and think I'll go with a rail mount and do the grilling off the swim platform on the port side so access to/from the swim platform via ladder or through transom door is not interrupted. Magma has a couple of different mounts available based on rail diameter. Anyone out there know the diameter of the hand rail above the trunk on a 2001 2500 SCR? I probably won't be back down to the boat until weekend and would like to get this on order.