Master 50 GT is the mid-tier inspected-vessel master credential — a step above OUPV with the same exam structure as Master 100, but capped at 50 gross tons of inspected-vessel authority.
TL;DR
Master 50 GT: 720 days sea service, full Master exam (including Plotting), authority over inspected vessels ≤50 GT. Common for mid-size charter sport-fish and harbour tour operations.
When Master 50 makes sense
If your boat is between 6 passengers (OUPV ceiling) and 50 GT, Master 50 is the right credential. Many charter sport-fish operators in this size run Master 50 because they don't need the additional 50 GT of authority that Master 100 grants.
Path from OUPV
Most candidates earn OUPV first, log enough sea service on larger vessels, then apply to upgrade to Master 50 — taking only the additional Plotting and General modules. The Rules of the Road, Deck General, Deck Safety, and Navigation General modules transfer if passed within five years.
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