Since the bending section is the part of the scope most susceptible to fluid invasion, it is good practice to submerge it first during leak testing - as a separate event. Before you submerge the entire scope, just insert the bending section into the water and let it sit for a minute or two. Carefully check for any leaks while this section is in its straight position. If a leak is found, remove the bending section from the water - do not continue to process the scope.