Victoria
Your watertanks are just inside the port and starboard hulls. They are Poly and have two vertical molded in depressions which act as baffles. The port tank I was able to get at the top face near the input by disassembling the word fascia which covers the fuel and water inlet hoses and acts as a housing for a 110V socket. As jdpandlp state though, they (tanks) are fully enclosed.
HOWEVER, I was able to install an ultrasonic NMEA2000 transducer for water level at the top forward face, next to the inlet attachment just under the 1/2 " plywood top to the cabinetry which doubles as the bookshelf on the port side . I used this unit because it is very thin (about 3/4") and easy to slide between cabinet and tank top. I have not tried that on the starboard side because I have the inside steering station and all the wiring from the circuit panels makes for a very tight space.
https://www.maretron.com/products/tlm100.phpFeel free to reply with more questions.
Cheers, lvwlv