I used to use a chene anchor on one end and a mushroom anchor on the other end of my boat. The chene would hold just about anywhere and was easy to get loose from the bottom.

+1 get ya some scrap metal and buddy with a welder. Me and a buddy made this one out of scraps he had around his barn. Prob a little bigger then what you need but I need a good strong one and total weight is 35lbs. But she will hold anything!

It's not just the anchor it's the way you use it. I have a river anchor with 3' of chain and I make sure I let out enough rope (I think the rule is 3 times depth). It holds my 20' fish and ski in LL winds with no problem. I just bought a sailboat and it came with this huge anchor that I have to lug around and find room for on the deck. I like that river anchor with the chain because it doesn't take up much room.

I have a mushroom anchor on my 14ft jon boat and when I tried it last weekend it held it just fine in a slow current. 20 bucks at academy.

I use a 4 fluke galvinized folding anchor for my 14 aluminum boat. About $7 at Academy. They fold up and lock for storage fold out to catch the bottom when in use.

I have a mushroom anchor i dont use cuz i dont like it. Doesn't hold well for me. I have a fluke anchor that works very good. They sell them at Academy, just get the smallest one cuz thats all u will need. Thats wut i have and with the chain kit they sell there too. It'll get the job done for u and won't be expensive for all.
I have a 17ft. bass tracker.

anything with a lip and i always go around 10 lbs.
if it still does not stick you can tie the business end of a rake to the anchor and it will help dig in especially when its windy and the waves are causing problems.

a 1 ton rotor with a 3 foot chain will hold a big boat. Bolt the chain to one of the studs but be sure to remove all the grease off before you take it to the lake.

flower pot + concrete + u bolt = anchor

%#-10# mushroom should work for your size boat.