Buy black fuel injection hose. The USCG rating is suspect at best, the garbage gray line out there is USCG approved.
Good point. Just because it passed a test and displays a USCG rating doesn't mean it's suitable for all applications.
The spec cited above is meant for permanent motor installations. The super-thick and stiff flame-retardant hose is completely inappropriate for the cramped space under the cowl of an outboard.
A little online research found there's a newer automotive spec "SAE R14" hose that's about the same diameter and flexibility as the common R7 low-pressure rubber hose, but it's "low permeation" like marine fuel hose--but without the double-thick walls that fights flame (for 2 seconds) that would earn it the USCG Type A rating. NAPA carries this under their "Barricade" trade name.
I also learned that "low permeation" means gas vapor in the hose won't seep out into the atmosphere, which keeps the greenies happy. An added benefit is the hose lasts longer because as the fuel vapor seeps through the hose it carries with it the oils and plasticizers that keep rubber hose soft and crack-free.
One answer I couldn't find is whether translucent urethane fuel tubing is superior or inferior to the black rubber type.