Well, yeah, islands can be car free but they can still be dependent on internal combustion engines. My wife's family owns a 110 acre island in a lake in New Hampshire. It is car free (no roads). Last time I was there I bicycled to the boat house and then canoed over instead of driving to the boat house and taking a motor boat over. In many ways non-motorized boating on the lake on a summer weekend is akin to riding a bicycle on a road with motor vehicles although non-motorized boats always have the right of way (unlike bicycles) and aren't subject to any silly "as far right as practicable" non-sense, many MB's pass too close while generating a large wake, sometimes deliberately. So, the LCF ideal in a maritime environment is living motor boat free (LMBF).