Small note here, seamark:type=* is intended for features todo with boats and other things that navigate on water. Since this was added on land features not close enough to water this is incorrect. The same applies to waterway=lock_gate since it to is  for water based features and from what I can tell must be placed on something like a canal, river or other waterway. If you want to indicate that there’s a locked gate somewhere you can add a gate and add the tag of locked=yes.

Happy mapping
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            Published using OSMCha: https://osmcha.org/changesets/149847522
            