Strange Tonnage

Yet another exciting tonnage determination question.

I work on a ship with the following on its COI

Which from my reading of the CFRs I assumed makes the ship useless for sea time between second mate unlimited and chief mate unlimited. Not just useless for avoiding a limited tonnage license but useless for any sea time whatsoever.

I looked up the tonnages on the PSIX (civilian MISLE) and asked the NMC what tonnage they use for determining licensing. The woman on the live chat said that they use the convention (subpart B) gross tonnage which would be the 4093


So basically I’m asking if I should trust the live chat. If shes right it means I can start working on my classes for chief and figuring out the money situation there (so very expensive) and if shes wrong it means I’ve got to switch companies basically if I want to ever advance my license,

This subject was discussed already earlier in this topic. Maybe be this helps.

How can you have such big difference between GT/GRT?
Is this a special type of vessel?

I guess I was just still confused since that thread seemed to be focusing a lot on the OSV license tracks which specifically address ITC tonnage. This tonnage disparity is just so large and technically the checklist says all sea time must be on vessels of over 100 GRT and the national license checklist says nothing about ITC. I hold a master 1600/3000 stcw license but I need to upgrade my national mates license which seems to ignore international conventions.

It is a 180 overnight guest passenger vessel.

I think you get unlimited tonnage seatime on that vessel.

This once again demonstrates how meaningless and arbitrary USCG Gross Register Tons are. They are worthless for determining anything of practical value. It’s a fraudulent scam. Mariners are the primary victims.

How do I get a job as “Chief Mate” on that vessel so I can get unlimited master?

Yes, I know the USCG only requires one 100 ton Master, and one 100 ton Mate or this vessel.

However, those officers get 4000 ton seatime allowing an upgrade to an unlimited tonnage master’s license.

Oh the wonders of the USCG tonnage and licensing debacle.

the checklist says all sea time must be on vessels of over 100 GRT and the national license checklist says nothing about ITC.

You answered your question right there.
CG uses the GRT for license, ITC only gets used if there is no GRT.

I do know of cases where people have gotten the CG to count the ITC instead of the GRT by proving that the vessel was run according to its ITC manning instead of it’s GRT manning on the COI. This was an OSV under 100 GRT and under 3000 ITC. It had different manning for inside 200 NM of USA shores and international waters.

In your case this will not work because your vessel is not manned with Unlimited officers or AB’s if it even has a manning for international waters.


My recollection is that t hey give you seatime credit or whichever tonnage admeasurement is highest, I.e., the GT.

That is not correct.

Thanks, thats what I figured. I don’t think I’ve ever gotten useful information from the folks that work the NMC website.

46 CFR 11.402

All required service is on vessels of 100 GRT or more AND 50% of the required service is on vessels 1600 GRT or more.
A Tonnage Limitation may be issued if 50% of the required service is not on vessels 1600 GRT or more; however, ALL required service MUST still be on vessels 100 GRT or more.
Limited to max tonnage on which 25% of experience is obtained, rounded up to the next 1,000 GRT, OR
Limited to 150% max tonnage which at least 50% of service was obtained rounded up to the next 1,000 GRT, WHICHEVER IS GREATER. Minimum tonnage calculated will be 2,000 GRT, when calculated total is 10,000 GRT or more, no tonnage limitations apply.

My recollection is that somewhere else, possibly in a NAVIC , Or in the Marine Safety Manual , it says they’ll give credit for the GT tonnage. Maybe I’m wrong, but that is what I recall.

That is just copied from the checklist on the NMC site. The evaluators don’t always seem to follow the same rules though, so who knows.

CG-543 Policy Letter 11-12.


“Service will be credited under the ITC tonnage if the mariner submits service letters…that the vessel(s) served on were operated in accordance with the manning requirements applicable to the higher ITC tonnage at all times”

Well I guess thats a nice black and white complementary rule to the CFRs. Well its just me and the captain and some temporary deckhands who’ve never sailed before so I doubt that counts.

I don’t want to cheat the system or try and be sneaky with my license, I just wish companies wouldn’t do it right back at us.

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