Thank you Curtis and YotaFreak for the replies. I ended up buying an 8lb fluke from the gas station at the harbor for $18. Set up shop in a cove off the main channel to test it out. Had plenty of traffic (and wind) by the boat, and the anchor held strong (mud, silt, sand, rock). It was probably the most abuse it would take compared to the rest of the season, minus July 4th. But for tying up in a secluded cove, with only idling boats passing by, it shouldn't be a problem at all.
Note: It doesn't fit under the front center, but it does fit under the front seat side compartments.