Good underwater detector recommendations

[poptab]

I'm looking for a good used ($400-700 range) underwater detector. Something I can alter to be very small and compact and use in 3-10 ft of water.

I have a Whites Surf P.I. Pro and was maybe looking for something different to go with it. Something with some discrimination? I would be using it in California.

Thanks

Poptab

 

[tomcatpl]

there is an old excalibur (with the horseshoe coil on ebay )i don't think it will go for more than 700