Assisting boats run aground in mud?
In the south SF Bay where I day-sail, it's pretty common to see sailboats run aground. Most of the Bay isn't particularly deep, filled in with thick mud, supposedly deposited by historical hydraulic mining. Mostly, a sailor has somehow deviated from the marked (with buoys and on the chart) area where it's deep enough to sail. The most comical exhibit was one particular race, apparently from the local YC (which I am not a member) out the channel from marina to the Bay proper, where it seemed that at least a third of the fleet had ran aground. The most common area to see people aground is where the channel opens up to the Bay, where if you ignore the buoys, it looks like it's OK to sail out into the Bay, but it isn't. Many days this area can actually be quite choppy.
My question is: what are my obligations here, in terms of good seamanship, and legally?
On more than one occasion, a grounded sailor has waved or hailed in a way suggesting that they wanted help (but not frantic enough that I was concerned they were in a serious situation, and not using an official COLREGS signal). I'm somewhat ashamed to admit I've never helped anyone. (I myself went aground once, when carelessly missing a buoy, and a guy fishing nearby in a small aluminum skiff helpfully pulled me off.)
My boat is 27', 4 or 5 tons, and 4ft draft, and has only a 9.9 HP outboard for auxiliary power. I'm not a particularly experienced sailor, and usually my crew is only friends who are mostly passengers. If there's any amount of chop, my size boat tends to have a fairly rough ride. Under some combination of these circumstances, I'm usually not particularly well-equipped to render assistance. Not knowing how long they've been grounded, my biggest anxiety is usually that I don't know if I can get close enough to heave a line without running aground myself--or in the confusion of pulling him off, accidentally drift onto the shoal.
Another factor is that assisting someone run aground is inconvenient, and could take a while, if they're aground fairly hard. There could even be negative legal repercussions if something went wrong, such as collision damage or injury. In all cases, people seem to be aground because they're disregarded basic navigational concerns, or they were pushing the limits in tacking. If there's no obvious safety concern, is there any real justification for me to help them?
But on the other hand, I suspect that I could help most of these people, and I definitely would, if it looked like a serious situation, or they hailed with a Mayday or anything like that. It's also likely that without help, some of the boats will eventually have to call for a tow, or possibly risk sinking as the keel lays over.
The main rationalization for not helping is that the area is has a steady population of other boats, which (due to it being the SF Bay) are usually much better equipped to pull off someone grounded: inboard motor, larger boat, better crewed. And if they are really in trouble, the area is in cell range, and VHF range to the coast guard, and not far from a significant port.
Can someone help set me straight here? I'd appreciate any insightful advice or opinion.