Members are referred to the Special Circular No.13-018 dated 10 December 2013. 
We had advised in it that all commercial vessels 79 feet (24.08 metres) in length or greater operating in a capacity as a means of transportation, that have discharges incidental to their normal operations and operating within three nautical miles of US coastlines and inland waters, were subject to the requirements of the VGP. The 2013 VGP would be valid for 5 years. EPA would have announced a new VGP till then, but in vain. As such, EPA decided to tentatively extend the 2013 VGP.  

To obtain VGP coverage, the owner or operator of a vessel who has a plan to call at the US ports within 12 months is recommended to submit a Notice of Intent (NOI) well in time for 18 December 2018, since NOI submission could not be permitted under the current rule.

EPA's website on the VGP is as follows.

https://www.epa.gov/npdes/vessels-vgp