Best to go on Thur or Friday. Less crowds. It truly is like being a kid in a candy store - and the clearance section - though small - offers a lot of small items at a very low prices.
I believe the sale prices get posted to their website on Wed. Also note - at least here in CT - West Marine will match defender pricing - except for S&H. You may want to drop by West to see if they'll price match. I've done it before.