[QUOTE=Capt. Phoenix;188445]No, it’s just not worth mentioning to foreigners because it doesn’t concern them. Panama canal and Suez canal tonnages are mandatory in order to transit, US GRT isn’t mandatory for anyone.
Also, he basically did mention US GRT, 100 cubic feet is 1 GRT, he just didn’t go into the specifics of the US system of tonnage hatches and exemptions, just as he didn’t mention the specifics of any countries domestic tonnage system.[/QUOTE]
The Moorsom System of tonnage measurement was not a specific US system. It was introduced by George Moorsom in Britain in 1854 and used by most nation before ITC’69 was made compulsory for new vessels in 1982 and universal for all vessels in international trade in 1994.
It is apparently still the basis for the US GRT, with whatever modifications and special rules that has been added over the years. but only for vessels under 500 GT, or that operate within US inland waters as defined by USCG.
Any US flag vessel operating in International trade has to be measured and certified according to ITC’69, if for no other reason to avoid being detained in foreign ports for non-compliance. (Costly for the Owner/Operator, inconvenient for the Cargo Owners/Shippers (who are mostly the US Government)and embarrassing, if the US flag should fall off the MOU White List.
As far as I understand inland waters are limited to inside the base line along East and West coasts of continental US and 12 n.miles from the base line along the Gulf coast.
How GRT/GT and STCW apply to vessels under 500 GT, such as tugs pushing large barges in international waters, or to OSVs working outside US waters, is a bit unclear from what I have read and heard.
If a tug [U]under 500 GT [/U]is pushing a great big barge from Seattle to Vancouver it would be on an “International Voyage”, and thus presumably having to comply with all IMO and ILO rules and regulations applicable to such vessels, but if it was bound for Nome Ak, or somewhere in Hawaii, would it be on a domestic voyage and exempt??
Why am I as a foreigner interested in this subject? Because it is interesting to learn how things are done in other countries. In this case, especially since US appears to be the ONLY signatory to IMO that see a need for having their own domestic system for just about everything. It is allowed for member nations to apply rules over and above IMO minimum standards for ships under their flag, but I’m hard put to see that being the case here.