It seems to me that there is starting to be to much emphisis on using a sentinal.If you choose to anchor in an area that is crowded, mabey to crowded,remember that a sentinel is suppose to work because of gravity pulling it downward. This effect is most prominent on a rode that is perfectly horizontal. No anchor rode is perfectly horizontal right? Because the anchor is on the bottom, and the boat is on the surface, the rode is diagonal and as the rode becomes more vertical , as with short scope, the effect of a sentinal lessens. A sentinal works because it changes the angle of the rode at the anchor, like chain does...thats why we HAVE chain down there. Picture your boat anchored on three to one scope, the wind at fifteen Kts. Your rode would be streight and tought from the bow to the anchor chain. Do you think a twenty Lb. sentinal is going to make a difference? It won''t. If you anchor in these conditions,use heavier chain. Or all chain. Or mabey avoid these places. It sucks, but I avoid them because even though I know I won''t drag, I know other people do. They do because they aren''t anchored properly. I also think anchoring isn''t a time to cut corners.