Fluke anchors...
 

Looking for one for the yak, found this but looking at the reviews I don't think people realized that you need chain for this type of anchor.

https://www.amazon.com/Kwik-Tek-Fluk.../dp/B0000ATY62

You guys think that chain could make this work or should I go for the next lightest fluke anchor?

I know the rule of thumb of rope length is 5:1 (if I get this, that rope will be put on my drift sock instead), is there a rule about chain length? I'm used to working with big boats so on this small of a scale it kind of eludes me.

Your right about the chain.......it is really the most important thing for just about any anchor.

But, you want it for the yak, not a heavier boat. I think for $20 that one you posted should work fine. I suppose you could put 5-6 of 3/16: chain on it but want to be weight conscious on the yak.

My first set with a Hobie grapnel anchor was expensive, as I couldn't for the life of me pull it free, even with the ability to stand up in my Hobie PA14. I'm going gallon milk jugs filled with sand or cement, with enough rode, so I can just pull the rode thru and sacrifice the free anchor.