Requirements: 

• RYA Powerboat level 2 certificate
• RYA VHF/SRC marine radio licence
• RYA Professional practices & responsibilities certificate (PPR)
• RYA Sea Survival certificate
• RYA First aid certificate (or similar approved by RYA) or STCW95
• ML5 or ENG1 Medical 

Once you have all the above, download the Application for commercial endorsement form, follow the instructions and post it to the RYA. 

Requirements: 

• As detailed above within the Powerboat level 2 section
• RYA National Powerboat certificate Advanced (only if issued before 1/1/2005) OR
• RYA Advanced Powerboat certificate of competence - achieved by passing the Advanced powerboat exam

Once you have all the above, download the Application for commercial endorsement form, follow the instructions and post it to the RYA.