venture patrols are more commonly seen in LDS units around here. But now more are starting to add Venturing to their program.
The biggest problem is that Scoutmasters do not support Venturing because they see it as taking their boys. Venturing is MORE scouting for active scouts. Some of these confused Scoutmasters try to create a venturing component in their troops to appease these youth. They are not allowed to use the program, uniform, or conduct any venturing activities without a formal charter.
I have boys that are registered with my Troop, my crew, a ship, and one or two other crews. Multiple registrations are a great thing. I have found that it makes for better scouts to have them active in more stuff even if it means that they miss an occasional troop meeting.