What the guys are sayin about the depth is spot on, thr more the better really but i normally use 2:1. An anchor you can get that wouldnt make you go ovet that is a digger anchor. They are black and gold and get the 15 pound size. Also has an auto release, i have yet to have it ever slip. Bit pricey at around 150 bucks
https://youtu.be/oxgwJwwUCYw
You wont regret it though.