Is a 3000gt itc a 1600 ton only

Hi I have a 500 master Oceans but do not undersatnd fully what a 3000 itc gt is is there any rating for a 500 or what does it take to get a 3000.


1600 GRT/3000 ITC… 500 GRT/500 ITC but you can ask for 3000 ITC OSV with the 500 but it will only be good for OSV’s

Thanks I understand