I often discuss safety on the Lake of the Ozarks but often fail to mention the requirement for boaters to have an operators license in Missouri.
The Missouri Boater Education Law went into effect January 1, 2005, stating anyone born after January 1st, 1984 must complete a NASBLA* approved boating education course and obtain an operator's certification in order to legally operate a vessel. This includes personal watercraft such as a "jet ski", or "waverunner". This law applies only to Missouri public lakes excluding rivers, streams, and "private waters". For the purposes of this law, the Lake of the Ozarks is considered a public lake.
Out of state visitors may use their own state's boating license or certification if it came from a NASBLA approved course, but you must carry the proof of course completion and a photo ID on you while underway. The law applies whether you own or rent a vessel while visiting.
If you fall into the age group requiring a certificate, getting caught operating a boat without one is a Class B misdemeanor punishable by citation and a fine. There is no stated exclusion for non-motor driven vessels such as sailboats, or even human powered vessels such as paddle boats, canoes, or kayaks (unless on a river or stream). Fortunately, most states within reach of the lake have similar laws so most visitors will either have one, or be excluded due to age.
*NASBLA - National Association of State Boating Law Administrators