N.H. Code Admin. R. Env-Wt 602.23
“Highest observable tide line (HOTL)” means a line defining the farthest landward limit of tidal flow, not including storm events, that can be recognized by indicators such as the presence of a strand line of flotsam and debris, the landward margin of salt-tolerant vegetation, or a physical barrier that blocks inland flow of the tide.
Source. #12806, eff 12-15-19