I've worked in the dive industry for several years now and a discussion that comes up regularly is the pros and cons with performing the "Controlled Emergency Swimming Assent" or "CESA" on the PADI open water course. In fact, the general consensus is that there are no "pros" in doing the vertical assent. If the student can perform the skill horizontally, which is more difficult, why bother with the vertical skill. Its reasonably common for the student to have to perform this skill more than once to reach the required standard which means multiple descents and assents for the student and especially for the instructor when they have multiple students. This has resulted in ear problems such as barotrauma and instructors have even been known to suffer Decompression Sickness from multiple CESA's. Both BSAC and CMAS have abandoned this skill and is it time for PADI to do the same? Lets face it, if a diver gets into a "no-air" situation (which they shouldn't!) and needs to get to the surface quick, they are going to do it! All the instructor should have to do it teach the the technique to do this in the safest way possible. If enough people are like minded, maybe we change the way things are done. I invite your comments.