I would go with the smaller vittie vault if you are going that route I will post the weight capcity soon so to the question of two grown man depends how heavy are they
Specifications:
Length: 12' 8" / 3.86 m
Width: 34" / 0.86 m
Hull Weight: 72 lbs. / 32.66 kg
Capacity: 450 lbs. / 204 kg