KG Loc: Treasure Coast, Florida

What's better for temporary anchoring for fishing near a reef? (As opposed to permanently anchoring with not much tolerance for dragging/shifting.)

Of the two options, is it generally better to go with larger/heavier anchor and shorter chain? Or would I get same or better holding power with lighter/smaller anchor on a longer chain?

The anchor difference is 14lb vs 9lb. The chain difference is 5/16" chain 4ft vs 10ft.

I heard it's the chain what's really holding the boat, not the anchor. So wouldn't a smaller anchor on a longer chain be as good or even better?

Fredfish Loc: Prospect CT.

The purpose of the chain is to keep the shank of the anchor parallel to the bottom, so the flukes can stay dug in. The anchor is what holds the boat, so it must be the proper size for the boat.
Up here, when fishing rocky areas we use a grappling hook type of anchor, also called a reef hook, with little or no chain. I don't know if they're allowed on the reefs down there.

saw1 Loc: nor cal Windsor

What size boat ya got KG?
That has a lot to do with the size anchor you need.
With the proper size anchor you only need bout a 4 ft chain.
However, be sure to let enough rope out so that the chain lays flat on the bottom. Other wise your anchor is not gonna hold you properly.

bapabear Loc: Blaine, Washington

The chain serves to hold the flukes buried, not the boat. The anchor holds the boat. What kind and size of boat.
What is the depth, What kind of anchor.

Papa D Loc: Mantweeka, Ca

I'm merging some of the info from your previous post.

Anchor type is a Fast Set (basically a plow)

You're interested in using a lift/retrieval buoy.

For most anchors dig-in-style (eg, plow, fluke, claw, mushroom...) anchors, the chain should weigh at least as much as the anchor. This weight lowers the angle of the anchor resulting in a faster set and better hold. It will also act as a shock absorber between the boat and the anchor. Keep in mind that this is for 7:1 scope. It is also the amount that is used by the manufacturer in determining the rated/recommended anchor size.

Since you are considering using a buoy lift, you'll want to have the chain weigh at least 10% more than the anchor.

Assuming that you'll want to anchor with low scope (less rode) for temporary anchoring you'll need to compensate by further increasing chain weight.

If you occasionally anchor in rocky areas, it would be better to go with a shorter length of larger chain than a long length of small/lighter.

Provided that the 9 lb anchor is the rated/recommended size for your boat then I would recommend using 10' of 3/8" or 7/16" chain (14 and 20 lbs, respectively). My personal preference is runs heavier because like to use a shorter rode and I hate having to reset.

Since the total weight would exceed the rated lifting power of the 12" buoy in your other post, you would need to upsize it accordingly (16"+). You can buy the buoy and ring on Amazon ( Welded Anchor Ball Retrieve Ring https://a.co/d/30ic3AX )

I would also highly recommend that you use an eye slice (and smooth hardware) to attach your rope to the chain in order to prevent the retrieval ring from hanging up on knots.

Here's the weight of chain in case you want to explore other options...
5/16 chain 0.876 lbs/ft
3/8" chain 1.41 lbs/ft
7/16" chain 2.09 lbs/ft
1/2" chain 2.4 lbs/ft

Papa D Loc: Mantweeka, Ca

A couple of additional points...

The goal is to have enough chain weight to allow for a couple of feet of chain to lay on the bottom at all times. This of course will vary depending on conditions. IF you're anchoring in extreme conditions you may have to double or triple what I recommended.

I've seen numerous websites recommend a chain length that is at least as long as the boat. However since they don't mention the chain size, I find this recommendation to be ambiguous. After all it's the weight of the chain that keeps it on the bottom. This rule also doesn't allow you to adjust for rocky bottoms.

After you've set it up and trying it out, pay attention to what happens when you have a big roller pass under -- if you feel a noticeable jarring (caused by all of the chain slack being pulled out) then you should add more chain weight.

All said, I consider the anchor as a piece of emergency equipment -- to keep me off of the rocks/reef/beach, out of the shipping channel, or pointed into the seas in the event of engine failure. The last thing I want want is an anchor that won't set or hold. Therefore I'll error on the side of caution (the heavy chain side).