Complex sentence: It is a very flood-prone challenging cave system, with many of its passages involving long wet crawls, and other sections have neck-deep water, and many of Leakey's explorations were conducted solo as few of his contemporaries had the necessary endurance.
Split into simpler sentences: It is a very flood-prone challenging cave system, with many of its passages involving long wet crawls. Other sections have neck-deep water and many of Leakey's explorations were conducted solo as few of his contemporaries had the necessary endurance.