Does the "100" in a "Masters 100 ton" mean anything?

[twistedtree]

I frequently see and hear people talking about the USCG Masters 100 license and a Masters 200 license. But from what I can tell, these are strictly colloquial terms and have no real meaning. As best I can decipher things, which is not easy to do given the convoluted and incomplete information that's out there, there is only a Masters license, and that license carries a tonnage limit, and a navigational range limit.

I suspect when some people say "Masters 100" they mean a Masters with a 100 ton rating. The schools are the worst offenders from what I can tell. Many advertise classes for a Masters 100, yet they can't control what tonnage you will qualify for. It might be 25, 50, 100, 150, 200, or more. It's the same class and the same test from what I can tell. All the rest is determined by sea time, at least until you get up over 200T.

Does this make sense, or is there actually a material difference between a Masters 100 and a 200 other than the tonnage rating and associated requirements for the same? And if they are different, how do 25, 50, and 150 ton ratings fit it? Do these licenses exist:

Masters 100, 25T?
Masters 100, 50T?
Masters 100, 150T?
Masters 100, 200T?

And what about these?

Masters 200, 25T?
Masters 200, 50T?
Masters 200, 150T?

[Capt.Alex]

You are correct that the 100 or 200 refers to tonnage. However, there is a difference in testing. A Master up to 100 Tons is the same test, just a difference in sea time on appropriate tonnage craft. There is a more involved test to get a 200 Ton. Then, there is a MUCH more involved test to get a 500 or higher. Each step up has an increased requirement for sea time.

[capttman]

The 25, 50, 100,200 etc is the tonnage the master is limited to. If you have a 500 ton master license you can run a boat up to 500 gross tons

[twistedtree]

Originally Posted by Capt.Alex

You are correct that the 100 or 200 refers to tonnage. However, there is a difference in testing. A Master up to 100 Tons is the same test, just a difference in sea time on appropriate tonnage craft. There is a more involved test to get a 200 Ton. Then, there is a MUCH more involved test to get a 500 or higher. Each step up has an increased requirement for sea time.

OK, so some of this is just sloppy language. What I think is really meant is:

Masters, up to 100T
Masters, up to 200T

For inland and great lakes, it looks to me like the base test and sea time requirements are the same for the 100 and 200, and the only difference is in size of the vessel where you logged the lime.

And that when you get to Near Coastal or Oceans is where there starts to be a difference. Does that sound right?

[Capt Phil]

It's been a while since I sat the exams but as I recall the Masters 100 ton refers to the tonnage of the vessel I was licensed to skipper (insurance companies were the most interested in the license) and the sea time of near coastal vs ocean going related to the period of time you had documented in either coastal or ocean going. Additionally, there were tow and sail endorsements that required proven proficiency/experience in either or both.
Because of the time spent in the towboat industry in Canada when I sat for my Masters 100 Ton, I was grandfathered in with a tow endorsement but that was back in the 80's as I recall. The most important thing on license renewal was maintaining seatime.
Everyone who graduates from a maritime academy like the CMA, is automatically licensed as a Master 1500 ton ocean going, I believe. That includes engine room as well as deck officers. Different unions, however, MEBA vs MM&P.
My memory is a little foggy on the details so feel free to correct, anyone? Phil

[gjordan]

One of the licensing schools used to sell a book that had all of the CG licensing requirements and how to go about the process. I loaned mine to someone 20 years ago and never got it back, but that book made it easy to understand what to do. I started with a 25 ton Limited Masters,Near Coastal, and kept very accurate records of my time and tonnage , and raised my tonnage as soon as I got the required time in larger vessels. I went all thru the 50, 100, 150 up to 200 ton. The next logical step would have been the 500 ton Masters, but the 500 ton Mates required less time, so I went with that as soon as I had the time. There was a large jump in testing difficulty going from 200 ton to 500 ton, and I had to do a 4 day fire fighting course. I had already done the radar course, so I didnt have to do that over again. I had previously done the aux sail endorsement , but if I remember right, that didnt carry over to the 500 ton. The last upgrade I did was the All Oceans endorsement. That was the stupidest exam that the CG ever had me do. I had many thousands of miles navigating with only charts and a sextant, and the exam had very little to do with real world celestial navigation. As stupid as the Oceans exam was, it made the insurance companies happy when I was doing deliveries. If you want to work your way up in Licenses, consider the time requirements for inshore masters also, since if you are a licensed master you can count your time a little different. Back to my original point, The book was an 8 by 11 spiral bound, inch thick treasure trove of information,and I would recommend calling all of the schools to see who sells the up to date version of it. Please post if you find the book. It might help others._____Grant.

[Sam Plan B]

100 ton refers to a vessel's internal volume / cargo capacity. A "ton" is a unit of volumetric measure derived from the space a cask occupied in sailing ship times. My Columbia 41 is documented at 16 tons net. The displacement is different. Thus, a 100 ton license would allow the holder to command vessel about the size of a tug boat. The more the tonnage the larger the vessel.

[mcarling]

For very very small vessels, the gross tonnage is about 20% of the enclosed volume, measured in cubic meters. For an infinitely large vessel, it would be 100% of the enclosed volume, but for the largest actual vessels, it's about 30% of the enclosed volume, measured in cubic meters. 25% is a good approximation for vessels in the 100 to 1000 gross tonne range.

The actual formula is: Volume * (0.2 + 0.02 * log10(Volume))

For the largest supertankers ever built, log10(Volume) is about 5.5. So 0.02 * 5.5 is 0.11. Added to 0.2, that's 0.31 or 31%.