You're here to relax and kick back - leave the ditch digging to the pros.
Usually out of view of lifeguards, we find a wild number of these projects when we are patrolling the beaches. Chief Harrison managed to snap a pic of this one while on routine patrol the other day. Just after requesting the gentleman to fill it in, it started to actively collapse (he's ok).
This is a seriously dangerous, potentially life threatening activity. There have been numerous incidents of sand hole / sand tunnel collapses (to include here on LBI), where the results are catastrophic.
Once more, we're appealing to our followers to be our eyes and ears. If you see this occurring, please report it to a lifeguard or beach patrol officer. Doing so can save a life.