Divers can explore the deeps but you can also snorkel here, or take a glass-bottom boat or submarine tour to get a glimpse of this watery world.
Diving is the best way to explore the waters. 
mnli hypothesis: Diving is the best way to explore the waters.  premise: Divers can explore the deeps but you can also snorkel here, or take a glass-bottom boat or submarine tour to get a glimpse of this watery world.