No licence, but I have the Canadian PCOC since '99 (when it came out), the Toronto Harbour Licence (involves essentially maneuvering a small outboard skiff around a marina and identifying some basic COLREGS stuff), and have passed the following courses: the 12-class "Boating" course from CPS, the 4 week "Coastal Pilotage" course from CPS, and a six-class Celestial Navigation course offered by a former CPS instructor at the club.
I also have an Astra IIIB sextant, a Freiberger Yacht sextant and a Davis 25 for the kid. I carry a hand-held compass and an old optical rangefinder, as well as a Trimble GPS, two Magellan handhelds and a Raymarine late '90s chartplotter. I have a Ritchie Globemaster with compensators at the helm and a KVH gyro compass. I also carry all local charts, although I tend to rely on Notice to Mariners over the radio as Lake Ontario doesn't have a lot of news in this regard.
Lastly, my watch has a recording barometer and a compass, but I have to get it five and a half feet off the steel deck before it will read properly! So that's a load of info and backup.
I would like to take the RYA Yachtmaster and then the Oceanmaster courses in Britain (I hold dual citizenship and thus it would be a matter of getting there and affording the time and cost of a few weeks in a B&B) because they seem to be the most respected qualifications around the world short of the actual "tickets" professional mariners or naval personnel can acquire.
The "six-pack" offered by the U.S. Coast Guard is considered pretty basic and Caribbean-oriented by non-U.S. sailors, as it is no more difficult than the basic licensing you need in most countries to sail at all. Alex is pretty up on this sort of thing. Of course, the vast majority of Canadian and U.S. sailors have little or no formal training at all, as the PCOC in Canada is a bit of a joke, but fractionally better than nothing, I suppose.
One point: The USCG will only certify U.S. citizens, which is fine, I suppose, but I would take the six-pack if I could, just to have SOMETHING. Canadian Power Squadron courses are quite similar, but they are NOT "official qualifications". I would have to go to "Canadian Sailor School" for that, and I'm a bit old to consider a career on lake freighters....