I don't know if this helps in your situation, but I find that where the bottom is muck, two things are usually obvious. Where people come in and out is usually the best spot for bling and there is less mud or compact mud in these spots because they have moved it with their feet. As nobody likes mud between their toes, people dive in much sooner and don't wade deep. The very shallow is usually a waste of time, because nobody is ever sitting in mud. As for recovering targets, I like a smaller scoop with lots of holes or even wire mesh - as long as it can reach down to where the mud is compact enough to stop the target from sinking. The advise about a sifter is very good. I have used a plastic Garret classifier in an inner tube too. I never tried using a pin pointer to find the target in the sifter, but it makes good sense. Usually, I just let it float with the sifter underwater and with time it clears itself anyway. I don't bother looking into the sifter each time. Instead, I dig until the signal disappears and drop it into the sifter and move on. The only time I check the sifter is if it is filling with debris and needs to be cleaned out or there are waves and I am worried that it might upset or there are people around who keep looking into my sifter.
