As the banner says, if you qualify, you can log it. All OCNA Challenge caches are locationless type, arranged as Geo-Art in The Gulf of Mexico.They are all "unknown" (?) caches, owned by a special Admin account, OCNAChallenges. Do you have an idea for one? Feel free to contact us.

I get around (Hider level 1): Hide OCNA Caches in 5 different States or Provinces. People have pretty much had the "no vacation caches" rule on Geocaching.com burned into their memory over the years, but here at OCNA, we accept two of their grandfathered cache types (Virtuals and webcams) that are suitable for "vacation cache" placements. In addition to that, two of our unique cache types not found on any other site are suitable as well; Guestbook Caches and BIT Caches. A few of our users own machine laminated BIT's hundreds of miles from home. Additionally, hosting events counts.

Verification: Please post your qualifying hides with your log, preferably in the http://coord.eu/OUXXXX format, and also keep in mind you can link to cache pages using our cache log editor, although is not mandatory. To see if you qualify, you can just look through your list of hides in your profile. It is also possible to do a  "my hides pocket query" on our site!  (follow these instructions, but substitute your hidden caches, rather than your finds ) and that .gpx file is easily imported into GSAK, or any similar stats program. We recommend a "gpx gc" file, and we also recommend GeoGet as a free alternative to GSAK, should you not be a paid full version user of GSAK.