I have been thinking about buying some property near the beach for STR, but haven't done much investigation yet.

Like any other market it takes a lot of investigation to find the property that fits expected results but with time and patience there is opportunity

I will look into this... good point and worth investigating.

W/o much info and familiarity, I suppose using a high level stats like the average RTP ratio of a city might provide a reasonable 1st filter to have a short list for further investigation.

Also investigate who is living there on what's going on before trying to bid. 

After further investigation that my broker failed to initially do I discovered that the last time the 10 year T-bill dipped below 3% was back in 2010.

Well, believe it, as it has happened, I spoke to the title company myself so this is not speculation or heresay.Apparently, as explained to me by the title company, BofA scans the public records and when they see a transaction sold for more than twice what it was purchased for (regardless of the amount of repairs needed - they don't care about that)they flag it and investigate.

Do any of you have any experience with what that could mean and how I could investigate it further outside of asking the tenant directly?

Investigator at market rate is, make sure your competitive yet not leaving money on the table, etc.

They won't all disappear but the word will travel fast when a few get placed under state investigations for brokering without a license.