If I packed into remote locations, I would want a rugged detector which could be easily carried and was waterproof to prevent water damage from rain or accidental dropping into the water.
Two recent detector models (Garrett ATX Extreme PI, and the Minelab CTX-3030) fit this criteria but are heavy and pricey. If you purchased either of the above detectors used in good condition at a reasonable price, you should be able to use it during your vacation and sell if for what you paid later as they hold their retail value well.
If I primarily hunted the Gold Fields and needed to detect in the water and on wet and dry sand where there is not a lot of trash I would choose the ATX Extreme PI which is optimized for gold prospecting. This selection would be subject to my being willing to dig all targets (including the deeper ones) and having the stamina to dig do so.
I would choose the CTX-3030, which has a visual display for advanced discrimination and selectivity - to detect in trashy areas on the beach as well and in parks. I would carry a pin pointer with this detector, even for beach detecting as it is unusually sensitive to small targets, such as ancient hammered wire silver coins found in Europe. Again, I would have to have the stamina to detect deeper targets.
In my opinion, None of the above detectors or any all terrain detector would be suitable for detecting in water(s) with strong currents, surges, anything but tiny waves, or for diving.
For this you would need a more rugged detector, which was designed for diving under such conditions. I would choose a Minelab Excalibur, Fisher CZ21, or Whites Beach Hunter 300, if I needed a detector with advanced discrimination capability.
Or I would choose any one of the below PI detectors below if I did not need/want discrimination and wanted deeper depth in the water: Tesoro Sand Shark, Garrett Sea Hunter Mark ll, Whites Surf PI Dual Field, Garrett Infinium LS
