Adding to the mystery, transflective is the only game in town for boat applications. You can get a nice fish finder like the Lowrance Hook Reveal 7 (I have one

Adding to the mystery, transflective is the only game in town for boat applications. You can get a nice fish finder like the Lowrance Hook Reveal 7 (I have one) with a 800x480 7" transflective screen for $290. That is including the external ultrasound transducer, signal processing chips, CPU, memory etc. So the display itself can't be much more than $100. The resolution is not huge, but still.