I haven't done much snorkeling, but the least pleasant of it was when the one-way silicone-disk water purge valve stuck or leaked, making it hard to blow water out of the tube and keep it out. A nice neoprene foam headband made my snorkel more comfortable and aided its floatation in case it and I were ever separated. It's kinda nice, but not essential, to have some form of louvers or whatever at the top end of the tube to deflect splashing water. If anyone has put a true valve of some sort at the top to block water but pass air, that could he helpful if it wasn't too complicated. As long as the purge valve works well, it doesn't bother me if water gets in the tube. It's my responsibility to purge it before I inhale.