I pack my Penn 706s full of grease. I also make it a point to put a bead of grease around the housing before putting the side plate on. The metal side plates on the older 706/704s make a very tight seal. The "newer" plastic side plates don't seal as well. I think all of this definitely helps the reels withstand dunkings. Penn makes a good blue grease that I'm using now. Before that I used the grease that The Surfcaster catalog sells.