Mr Foster, thank you so much for taking my question.
I have the Surfmaster Dual Field PI, with the large yellow coil. I do not believe that there is a larger coil.
I snorkel - no scuba. Generally, I work in water up to around seven or eight feet deep, and all the way back to the shore. I have an extension on the detector, so with my long arms I can snorkel and reach down to the bottom. Also, I dive to the bottom, and dig everything up by hand. Rocks and small boulders are no obstacle. I use a garden trowel, and no longer use a scoop.
I hunt in the Mexican Caribbean. The sand is composed of pulverised coral. The ground does not appear to be mineralized with iron. I run the Dual Field at maximum gain, with sensitivity close to maximum. If there are many waves, and the detector is more prone to falsing, I adjust the sensitivity to make it quieter. If the water is lake-like, I use greater sensitivity. I run full gain all the time.
In a number of instances, I have recovered lead cloth bale seals at around 16-20 inches. These seals weigh between 30 and 35 grams. I can detect them deeper than rings, I assume due to weight and density.
Also, I can detect old Spanish musketballs at probably around 15 inches. They weigh about 20 grams each.
Here is a recent pile of gold and platinum rings, now at about 213 grams. As you can see, most all of the rings are wedding bands. I can pick up large gold rings at around 16 inches. But, the thinner gold rings, maybe 2-4grams, are coming in at maybe eight inches to a foot, tops. And, the limit is when the signal is faint, and "iffy". Whenever the signal is faint, I pretty much always dig!
What you will notice is that I have never found a thin delicate ring with a large precious stone on it. Even out of a hundred gold rings, none are thin and delicate, with large stones. My theory, for whatever it is worth, is that thinner high dollar rings, with big stones, are harder to detect than the heavier 18k bands, which are more massive. I say this because the thinner gold rings in general are hard to pick up if they are beyond eight inches. So, this is another reason why I am interested in a more powerful detector comparable to the Surfmaster. I would like to be able to hit a heavy 18k ring at close to 20 inches, while getting more depth on the thinner rings, if this is possible.
My sense of depth is based on the length of my forearm. From fingertip to elbow my forearm is a lanky 19 inches. And, the distance from my fingertips to the middle of my forearm is about 12 inches.
So, once the objects pop out of the bottom of deeper holes, I put my arm in to try to get an idea as to the depth of the hole, based on the distance my arm goes into the hole. I do this on notably deep objects. If it takes over twenty minutes to dig a signal, I usually take a break, and look for some shallow stuff to dig, and then return to finish digging out the object. In some cases, after a good twenty minutes of digging, I have unearthed fairly large rings, that were deep, and under rocks. But, I don't think that I have found a ring beyond 16 inches, whereas the lead cloth seals come in deeper, and can take even longer to dig out.
It would seem to me that after thousands of hours of using the Surfmaster D.F, I am becoming familiar with its limits. In areas that are sanded in elbow deep at about twenty inches I can dig to the bottom by hand, but I cannot get a signal on anything, unless it is the size of a pocketknife, or larger. Nothing smaller comes in. No rings, no coins, nada. Yet, such areas are heavily frequented by snorkelers and swimmers. So, there are probably thousands of small objects just out of reach that could be dug by hand. But, currently I either have to wait for a hurricane, or find a better detector that runs a few inches deeper.
From the little I have gathered, I suspect that maybe you developed a deeper running PI? Would the Aquastar do the job for me? Could I hit a coin, or a ring, with the Aquastar at around 20 inches??? Unlike other detectorists, I reject the notion that the Surfmaster goes too deep. And, I reject that idea that digging fishing weights is somehow "unwanted". Fishing weights oftentimes are found in the same range as heavy gold. But, in some cases, these objects could be just a few inches out of range of the Surfmaster.
Any help would be immensely appreciated. The main thing that I am looking for is a few more inches. If I could hit a heavy ring at 20 inches, it would be ideal.
Thanks,
Ben