RYA powerboat courses are primarily for those using small powered craft such as RIBs, dories and sportsboats that don't generally undertake long or offshore passages. 

The types of commercial craft requiring this level certification are typically: charter fishing boats, small passenger launches, local tour operators, harbour patrol launches, construction site safety boats etc, for day time operations only. 

If you will be using larger boats with accommodation and the capacity to cruise or work further offshore you are likely to need a certificate within the motor cruising programme such as Day Skipper, Coastal Skipper or Yachtmaster Offshore. If you are operating larger, more powerful open craft or operating further offshore or at night, you will need to look towards the RYA Advanced Power Boat Certificate of Competence.  

If you need a Level 2 Powerboat Handling certificate in order to work on a commercial craft subject to the MCA's codes of practice, you will need to get it commercially endorsed. You can then work on commercial vessels up to 24m in length, operating in category 6 waters - that is up to 3 miles from a nominated departure point in fine weather and daylight hours.