depth gauge and Raymarine

[kurz]

Hello
I think about installing a depth gauge.
My idea ist to connect it to the raymarine ev-100 system. So the display p70 is already available.
So why not take a combination sensor with water temp and speed through the water and mount it extern at the stern? Then go to the backbone somewhere and watch the data at the raymarine p70 display?

No more displays, all data at the same place...

Good or bad idea? Which sensor could fit?

Thanks all

kurz