Thanks for the compliment Steve O.
As far as running the 6a at the beach ( assuming salt water ), one of the things to consider is the location. If the 6a can ground balance in normal mode, run that mode. It will be more sensitive to smaller low conductive targets. There are some beaches where this can be done in the wet sand ( and in the dry, normal mode almost always works), but for most salt water beaches in the wet sand, the 6a will probably have to be run in salt mode. And if you get into the suds, salt mode is probably the only mode that will work.
Make sure you ground balance and as stated in a previous post, if you cannot ground balance ( use the bobbing method, which is explained in the manual...by far a better way as you get a more concise balance as opposed to the quick pin point gb method), run it at 5. One thing though....if there is an abundance of nails and iron, upping or lowering the gb setting can help with some falsing. Have to experiment and test several areas to see if the gb control can help out.
Sensitivity setting is condition based. Make sure once you ground balance in all metal, that you lower the sensitivity when switching to discriminate mode. The 6a will tell you it is running at a higher sensitivity than it should by falsing more than usual and often. To start off, I suggest in the 2-3 range. I have found in the 18+ years of using mine, that anything past the 5-6 range does not increase depth and actually becomes a detriment due to additional falsing. But be aware that not all CZ's are the same, and you may be able to get more depth in the 7-8 range as opposed to the 4-5 range. Experiment but err on the side of caution. A stable CZ is MUCH BETTER than a hot one at the beach.
All metal vs discrimination can pretty much be determined by conditions as well. If there aren't a lot of targets around, all metal may be the way to go as the coil is now fully charged and you get more optimal coverage. I hardly ever run in all metal, but that is because it is hard to switch back and forth from all metal and discriminate mode due to how I have my 6a mounted. If I am running a bigger coil, and have the unit hip mounted, then I sometimes run in all metal.
As always, if running in discriminate mode, I state run in ZERO (0) setting. You want to hear not only all the iron, but it helps immensely with learning how to distinguish between real high tone targets ( ie, good targets) and the low tone/high tone iron falsing wrap as well as hearing the blasting harsh shallow iron tone as opposed to the more mellow, sharper high tone that signifies a good target. Only experience and using the machine will you be able at some point to hear the difference...but you will not learn the difference between an iron wrap high tone and a valid good target high tone, if you run at discrimination setting 1 or higher because you will never hear the low iron tone ( hope that makes sense !).
Sweep slow, over lap the sweeps and always hit a target from multiple angles. If you get a high tone or mid tone repeatable from sweeping at different angles, DIG IT. If there is an abundance of low tones mixed in, and the target is shallow, it's a very good chance is garbage. However, if the target is deep, dig it up. Lots of times a deep goodie will ID with low tones mixed with a mid or high.
As far as the volume setting goes, that is a personal preference. Cool thing about the 6a is that is has the modulated audio, so settings 5 and less will have the deeper targets sound fainter. Cool way to determine a depth range without having to use the pin point method. Since I have my 6a mounted on a straight shaft under my arm, I don't have access to the controls nor can I see the meter, so I hunt by tone and sometimes use the modulated volume to help. Then there are times when the wind and waves are loud, so I run in the 8-10 range because I don't want to miss any target. Depth range is not that important since I am digging all high and mid signals anyway.
As far as coil size....most here see me post about using the 8 inch coil about 90% of the time. I just love that coil. Super easy to pin point by Xing the target so I don't have to use the pin point button, and the coil fits inside the hole with a single scoop out. I can search the sides and wiggle the coil a few inches back and forth, without having to scoop out additional sand when using a bigger coil. I have the 10.5 inch as well as a Sunray FZ12 and only use them on sanded in beaches or when the targets are very sparse. To me, ground coverage and depth is less important than sensitivity, coil control and ease of pin pointing. The 8 inch coil has less coverage and probably has about 1-1.5 inch less depth, but it makes up for it with better sensitivity, less falsing, I can swing it all day and I already mentioned the super easy pin pointing. If you get a chance to use the 10.5, use it first before buying one....you may find out the 8 inch coil is the best. For me it is but that is how I hunt . What matters most is what you prefer and where you hunt.
Bottom line is, set it up right, swing slow and low, overlap the sweeps and when you get a hit, investigate it from different angles. Repeatable high tones or mid tones must be dug !
As far as hunting tactics, there are lots of great posts on how to attack a beach. Obviously you want to hunt where the people were. But there may not be obvious signs of that. Hunt the out going tide into the low if possible. Run perpendicular to the water at first going up and down ( from the med wet sand to the suds) to try to get an idea where the target line is. Once you see that there is a pattern, switch the attack and hunt parallel to the water on that line. If you hit any nickels, deep quarters or sinkers, that is the area to grid, from all different angles. If you start hitting deep zinc pennies, pull tabs and aluminum, move on. The coins and gold rings are probably too deep. Same with mushy sand...if you are sinking 3-4 inches down, get out of there...not worth the trouble.
Main point....HAVE FUN and be careful. Watch those waves and those rusty nails.
