Looking for some cheap weekend fun? Break out the clamdiggers, baby, ’cause you only got three days left to dig a few of these good looking bivalves out of the sand and bring ’em home to mama.The Washington Department of Fish and Wildlife announced yesterday that two ocean beaches, Long Beach and Twin Harbors, will be open for razor clam digging this weekend, the last dig of the season. You’ll need a license to do it, but it looks like $4.93 gets you a 3-day razor clam license, which isn’t so much for a weekend’s worth of dirty jokes about clams.I’m not experienced in bivalve excavation, so I did a little, um, digging. It turns out there are very specific rules about how many you can take (15 per person, per day), what utensils you can dig with, and where exactly you can dig. Here’s a nifty how-to guide, in case you’re curious about the difference between a dimple, a doughnut, and a keyhole.Dan Ayres, coastal shellfish manager for the WDFW, says that you’ll have the best luck digging about an hour before low tide, so plan for an early bedtime.DETAILS:Two beaches are open for digging this weekend to those wearing the appropriate license on the outside of their clothing. Digging must be completed by noon each day.Friday, May 4: Twin Harbors only, low tide 8:35 a.m.Saturday, May 5: Twin Harbors and Long Beach, low tide 9:12 a.m.Sunday, May 6: Twin Harbors and Long Beach, low tide 9:50 a.m.