Has ferry got enough exits?

I HAVE noticed that the only exits on the Hongkong to Macau ferries are situated on the lower deck and that passengers on the top deck have to descend a narrow staircase to reach these exits.

I am curious to know how top-deck passengers, in the case of an emergency, could be evacuated quickly, given that the number of exits appears inadequate for the number of passengers who would need to get out and the staircase to the lower deck is so narrow? NAME AND ADDRESS SUPPLIED