The AHPC data I got from OZ for their Taipan 4.9 uses 40 mm x 1.6 mm. The 4.9 pole is 3250 mm long (10.66 feet). I don't know about the Capricorn F18 pole. This 40 mm diameter is set up for their cool midpole snuffer to slide right on to. This is the same dimensions as a spar from a Sunfish. New that is only $80 and I think it is 14 feet. They often can be found broken at the 12 foot mark and uaually very CHEAP! Should work well for an F16 rig and maybe F18.
Contact Robbie and Jill for AHPC parts. They will have snuffers, poles, etc. And here in the US!
Happy Birthday, all you U.S.-icans!