I am using mkgmap-r3392 In my stylefile there is the following parameter generate-sea=multipolygon,floodblocker I am getting the following error Unknown sea generation option 'floodblocker' Known sea generation options are: multipolygon use a multipolygon (default) polygons | no-mp use polygons rather than a multipolygon no-sea-sectors disable use of "sea sectors" extend-sea-sectors extend coastline to reach border land-tag=TAG=VAL tag to use for land polygons (default natural=land) close-gaps=NUM close gaps in coastline that are less than this distance (metres) floodblocker enable the floodblocker (for multipolgon only) fbgap=NUM points closer to the coastline are ignored for flood blocking (default 40) fbthres=NUM min points contained in a polygon to be flood blocked (default 20) fbratio=NUM min ratio (points/area size) for flood blocking (default 0.5) I am wondering, why floodblocker is listed as known option but unknown at the same time. What is my error here?