Up to 15 tons all that is required is SVOP, Med-A3, ROC-M and some first aid.
Your boat should have a C license # as well and, all the 'proper' gear that goes along with that.
If you don't have a C-license # now, you probably won't get it till the end of summer. The feds are super slow handing out that kind of documentation.
Skipper insurance is an extra $500/year too. gl