How many Marine Surveyors in US and worldwide?

This is a difficult answer as marine surveying is an unlicensed activity and many are not registered with countries or states. There are professional memberships such as SAMS or NAMS that have listed members on their website. The last seminar I attended last year, a speaker there said he estimated there are approximately 2,800 professional marine surveyors worldwide. I have no factual proof I can present for this estimate however.