Seaworthiness of modern fishfinders (and opinions on size)

I can hardly see the smaller screens so I prefer 5" models. I'm on my 6th or 7th kayak fishfinder and currently using an Elite 5 Gold. For the type of fishing I do (70% saltwater), my favorite was the Humminbird 565. If I was to buy another FF, it'd probably be a 500 series Humminbird with gps. With the 83/200khz transducer...not the DI or DSI version.
For dielectric grease, just apply more once every 3 months, depending on how often & where you fish.
The Navionics charts are loaded onto a micro SD card that you insert into the head unit. Then you can go into the menu and select the Navionics charts or base charts. The base charts are easier to view IMO because the depth contours in the Navionics charts are a lighter color/shade. (Btw I wonder if I can change the depth contour line color?)
You can make the Lowrance 83/200 and DSI transducers fit into the Ocean Kayak scupper mount. It just takes a little tinkering to get it right. That method Paddleboy posted looks like a really good option.

For the type of fishing I do (70% saltwater), my favorite was the Humminbird 565.

Any particular feature/reason you prefer the Humminbird 500s over Lowrance? I'm picking up a Lowrance Elite 5 Gold tomorrow ($399 at West Marine, $170 off MSRP) but just curious about your preference.

Which West Marine are you heading to?  Know most of the employees at the stores from sausalito to Santa Cruz.  I can tell you who to go see.

 ~Bill

Which West Marine are you heading to?  Know most of the employees at the stores from sausalito to Santa Cruz.  I can tell you who to go see.

 ~Bill

Oakland store on Livingston St. Probably going to swing by there and pick up my Elite 5 on the way to work tomorrow morning.