Good evening Chris. The cost is $10.00 daily or $25.00 for the week. Please call the resort directly at 843-363-3400 should you need personal assistance.
Sorry I do not know the answer as over the 12 years we've been going we've never rented!!
So sorry for the delay. I believe it was $30 for the week, but I think my husband got a price of maybe $18 for three days.
Get an answer from Marriott's SurfWatch staff and past guests.