It should only be a few days. The same as your ham license.
It depends on how long it takes the COLE to send it to the FCC for processing.
I don't understand your question about Element 8. Did you allready pass it?
All they do is print "Ship Radar Endorsement" on the license under "Special Conditions/Endorsements".
I suppose if you pass it later on they just send you a new license and update you in the database.