Re: fish finder
I'll presume you're asking about the transducer installation here, since it should be obvious the console mounted fishfinder display can be installed with the boat in the water.<br /><br />IMHO the only way you can install your transducer with the boat in the water is if you're using a shoot-through-the-hull transducer.<br /><br />Otherwise, if you're using a through-hull transducer, how would you keep the boat from sinking

after you cut the hole through the hull for the transducer? (Yes, you could build a cofferdam, but do you have the expertise to do that?) And if you're using a transom-mount 'ducer, how would you drill the mounting holes underwater, how would you keep water from filling the holes, and how would you seal the holes against continued water entry leading to eventual rot or delamination

?<br /><br />So seems to me that unless you've got a shoot-through-the-hull transducer, you'd be best off hauling the boat out of the water. Good luck.