Now that Danforth has lost it's patent on what is now referred to as a "Fluke" anchor, there a lot of cheap clones out there. The one that is particulaly annoying to me is one that's made out of Aluminum.
For your boat a 12# (Real) Danforth should be fine for a lunch hook at the sand bar. Danforths are particularly suited to good holding in sand. Weeds can be a problem though. I like the
Danforth Hi-Tensile because it is forged steel and very sharp at the tips and digs in more quickly than the regular stamped steel Danforth.
The only other anchor I've used and with great sucesss in salt water was a CQR Plow..(The Original plow.) My 32 foot 10,000# sailboat had three anchors aboard.
12# Danforth Hi-Tensile
22# Danforth Standard
25# CQR Plow.
Each had 20 feet of chain plus nylon. The CQR was my main (working) anchor housed in a roller chock at the bow with 100 feet of chain in the chain locker up forward with another 75 feet of nylon at the inboard end.
BTW: A really easy way to carry chain and nylon rode around the boat if you don't have a chain locker, is in one of those
heavy duty canvas tote bags. Just feed the chain and rode into the bag starting with one end. When you get to the bitter end..shackle the end of the chain to the web handle on the bag so you won't lose the END.
NB
PS: Except for the working anchor in roller chocks at the bow, the other two anchors (in wood chocks.. and un-attached to their bagged rodes,) were stored seperately back aft.