The reef represented by relation 17987327 will not be rendered correctly as the reef tag has been duplicated to the outer way 1312080299. 

The tags need to be on a closed way OR a multipolygon relation. Not both. 

For more information see: https://wiki.openstreetmap.org/wiki/Relation:multipolygon#Usage

https://wiki.openstreetmap.org/wiki/One_feature,_one_OSM_element