Out of those I would recommend the Minelab or the nokta. Then if you decide to upgrade later, you would be familiar with the tones and different settings of whichever brand you chose. I’ve went back to a Minelab equinox for now. I had a xp deus 2 and ended up selling it. I started with a Garrett AT pro, but realized fast that Garrett is way behind on technology. Technology that makes a huge difference too! Then went to a nokta and actually really enjoyed it, but the Minelab is when my finds really picked up. I’ve not been going as much lately but I know you can’t go wrong with Minelab. The equinox 600 and 800 have an issue with leaking water in to the control box, but I think they figured out the problem with the later 700 and 900 models. I’ve not used a vanquish series detector, but have always heard wonderful things about them. That new 560 model looks like a dandy! The control box isn’t waterproof, but from the coil all the way up the shaft is, so as long as you aren’t diving you should be ok. They can handle a little rain no problem! Sorry for the long explanation, but it’s something I was really passionate about for a little while. I’ve found some really cool stuff, in places people said I wouldn’t find anything. It can be so much fun and makes for great exercise! Good luck with whatever you decide! Hopefully you’ll find the big one!
