As seen here, seaplanes have these, or they'd be at the bottom of the sea
... to a seaplane by a line that is intended to dig into the bottom below the 
water or... [DOC] [TLE]   "Lost City"    - RuLit ... [PAR] I took a fast train to Paris last night, planted myself here and checked with the 
poor desk clerk every fifteen ... "I assume Dirk and Rudi have been alerted?