The tourist industry is heavily based on the promotion of Napoleon's imprisonment. A golf course also exists and the possibility for sportfishing tourism is great. Three hotels operate on the island but the arrival of tourists is directly linked to the arrival and departure schedule of the RMS St Helena. Some 3,200 short-term visitors arrived on the island in 2013.

Answer this question, if possible (if impossible, reply "unanswerable"): Tourism is completely based on what arriving to the island?
the RMS St Helena