There will be an open mapping for several days straight. Identify the high tide in your area and map nearest that time. If you can map this same area over the 4-day period (at high tide), this will be helpful.
This mapping should be done in a 2018_KT_YOUR CITY region in the October 7 CTK Dress Rehearsal Mapping.
If you are not in a city specific region, use the Training Region you started out in.