▁with ▁Master ' s ▁Up gr ades ▁r ated ▁by ▁t onn age ▁of ▁ 2 5 ▁G ross ▁T ons , ▁ 5 0 ▁GT , ▁or ▁ 1 0 0 ▁GT ▁incre ments . ▁The ▁Master ' s ▁upgrade ▁allows ▁the ▁holder ▁to ▁operate ▁ins pected ▁vessels ▁as ▁well ▁as ▁un ins pected ▁ones . ▁The ▁total ▁number ▁of ▁passengers ▁is ▁limited ▁to ▁six ▁or ▁fewer . ▁Non ▁U . S . ▁citizens ▁may ▁be ▁restricted ▁to ▁und ocument ed ▁vessels ▁with ▁a ▁ 5 ▁net ▁ton ▁limit . ▁ ▁Typ ically , ▁an ▁O UP V ▁Cred ential ▁is ▁used ▁in ▁the ▁context ▁of ▁small - scale ▁fish ing ▁boats , ▁SC U BA ▁boats , ▁wh ale - watch ing , ▁and ▁the ▁like . ▁▁▁ ▁To ▁obtain ▁an ▁O UP V ▁Cred ential , ▁ 3 6 0 ▁days ’ ▁experience ▁on ▁In land ▁or ▁Near ▁Coast al ▁waters ▁is ▁required . ▁Of ▁the ▁ 3 6 0 ▁total ▁days : ▁▁ 9 0 ▁days ▁must ▁be ▁within ▁the ▁last ▁ 3 ▁years ▁▁ 9 0 ▁days ▁must ▁be ▁on ▁Great ▁L akes ▁if ▁the ▁applic ant ▁wants ▁to ▁obtain ▁a ▁Great ▁L akes ▁R ating ▁on ▁the ▁license ▁▁ 9 0 ▁days ▁must ▁be ▁on ▁Near ▁Coast al ▁waters ▁to ▁obtain ▁a ▁Near ▁Coast al ▁R ating , ▁which ▁also ▁qual ifies ▁for ▁In land ▁and ▁the ▁Great ▁L akes . ▁ ▁O UP V ▁Limited ▁Cred ential ▁The ▁O UP V ▁Limited ▁License ▁is ▁a ▁very