Ya, but can you really trust a guy named Bruce to advise you on an anchor! Personally, I think a Stoo Anchor would be better!
I also use my boat for diving as well. I carry a small 15 lb mushroom for anchoring into rock bottoms here. Everything else gets impossibly snagged. Bear in mind that I always have a tender in the boat, and if it's snarly out, I will hand-place the anchor when I am down. I find that a serious hunk of chain really helps it hold as well. (The chain weighs at least what the anchor does...)
But I also carry a larger Danforth anchor for mud bottoms as well as the rocky stuff. It holds well. If we are camping, I string both out as well as a line to shore...
I adopted the bucket storage method years ago for the mushroom which I use 95% of the time. The other is held in set of chocks along with it's chain.
As an aside, the only time I "lost" a boat while at anchor (and about the only time I didn't have a tender in the boat) was when the shackle holding the line to the chain came undone. I was diving and it let go ust as I approached. I was able to grab the end of the line and get back to the boat as it was drifting away in a strong breeze! Fortunately, it was a 2.5' SIB and was easy to recover. What I'm getting at is the type of anchor is moot if the shackle isn't sound and secured properly!