I generally just use the "create a dive spot" on the 'diveworld community' page, use the little map on the site and drag and drop the pin to the location i want, and that has worked quite well... No numbers or anythingthen i portal that dive to my SDA.
DiveWorld - uemis DiveWorld
Yeah, how does that work on sites where you don't have good visual?
For example there is no land around for miles or a place you never dove before and not familiar with and it is on an island you never stepped a foot on?