I have used both machines, and can tell you the following. The <img src="http://www.garrett.com/images/hobby/products/lcdisplay/seahunter_display.jpg"> and the <img src="http://www.garrett.com/images/hobby/products/lcdisplay/infinium_display.jpg"> are both PI machines and both will cut through salt water beaches, and some of the nastiest types of mineralized soil imagined.
The <img src="http://www.garrett.com/images/hobby/products/lcdisplay/seahunter_display.jpg"> is the easiest of the two to operate. It is basically a turn on and go machine, make a few adjustments and hunt. Now, as with most PI's, you have to dig all targets. So.....you end up getting arms like Popeye, but also get the deeper targets left behind by others. You can improve the odds of digging junk by carefully picking your sites. Hunt areas not littered so much with junk, or just hunt the water where it comes up to waist level or higher. Also, if you hunt a hunted out beach, you will soon find out that a PI finds many targets missed by other machines in an area.
The <img src="http://www.garrett.com/images/hobby/products/lcdisplay/infinium_display.jpg"> is a different machine from the Garrett Sea Hunter. It can be fine tuned to remove interference from radios, power lines etc. It can also be ground balanced to achieve maximum depth. Now, it also loves iron targets, as do all PI's, however, the <img src="http://www.garrett.com/images/hobby/products/lcdisplay/infinium_display.jpg"> has the ability to ID certain targets as iron, using the iron check and leave them in the ground. So.....you can essentially just look for old copper and silver coins and jewellery, as these targets will sound off as a "low-high". Iron, gold, large pieces of iron will signal a "high-low" sound. A large target makes the audio sustain itself considerably longer then a smaller target.
So.....using the <img src="http://www.garrett.com/images/hobby/products/lcdisplay/infinium_display.jpg"> allows you to:
1) Size targets by the length of the audio sound.
2) Define iron by using the "iron Check" on the Infinium
3) Cut down your junk ratio by hunting "low-high" signals only
4) Use various size/type coils to fine tune your searches
5) Pick your areas wisely to increase your good:bad target ratio.
But......you have to learn to use the Infinium. It doesn't behave like a single signal or some multi frequency machines. It has it's own way describing targets under its coil. The success of the machine is usually dependent on the way it is set up and used. And there have been hunters who have done well cleaning up hunted out lakes and saltwater beaches using the Infinium. The Infinium has been described by some to be the deepest PI machine available today.
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