Pi wireless setup as passthru router

I have a sonar with wireless hotspot sending data back from it. Can the pi be setup to see hotspot and incorporate feed to surface thru pi. I am trying some experiments with wireless out of the water first then in the water to determine useable distance, if any. A white paper i found shows that it is possible to send data at very short distances thru fresh water so looking for results in saltwater. Probably wasting my time but …u never know till u try.
Any advise welcome

You will not get any practical distance through water with RF. This method works reasonably well with good coaxial cable, though: GoPro Underwater Wi-Fi Cable Setup.

There is not enough information about what you are trying to set up or accomplish to advise you on network configuration.

@jwalser I understand the difficulty of wireless thru water so was thinking along the lines of the link u have sent.
The sonar runs a hotspot that auto links to an app on phone but at the end of the day it is just a hotspot that i have password for. I would like to send that sonar and depth data up to surface thru pi and then to app to show sonar. I also would like to tap into data for bottom tracking.
I will rethink and get back to u