1st, Good Choice..!
In my opinion, I would mount it on the console, that way you can tilt it if the sun glare hits at a wrong angle, the screens are VERY bright and this is GENERALLY not an issue... plus you keep it away from sticky fingers...!!
However, the units are not as watertight as they should be, and mine got interior moisture from leaving it exposed..
Yes they come with a plastic cover that is supposed to keep the screen dry and protect it from UV damage, however, I prefer to pull mine and store it inside.. I smear a touch of dielectric grease on the face of the Female plugs,(one on the unit, and one on the wiring harness, so that they pick up a light costing of the grease on the pins to retard any corrosion that may build up over time.. I think that the pins are gold coated, and it really should not be a problem anyway.. call me paranoid.. but I believe in a touch of insurance..
One of the things that I would do differently, is the transducer mount.. seems that the transom mount transducers need to me mounted EXACTLY like stated in the instructions, or they will not give you accurate depth readings at speed, most brands don't anyway.. However, if the transducer is mounted low enough to where the midline of the transducer is even with the bottom of the hull when level, you will get the best results.. by all means read the darn directions before you drill... the shop that installed mine mounted the brackets a tad high.. and it gave me heck until I remounted it...
To get an accurate depth reading at speed, you really need a thru hull transducer mounted near the transom,,, however the cost there is a less that accurate water temp reading.. I think that this unit is capable of running multiple transducers thru a network cable, but that is more than I have been willing to tackle..
One of the things that you will want to do is check and see which software version you have in it.. here is a quote from their download page and a link to it... It depends on how long it has been setting on the dealer shelf...
http://www.lowrance.com/en/Downloads/Pr ... ion-files/
"How to see if your HDS is already using version 3.5:
1. From a chart or sonar page, press the MENU key twice to activate the Settings menu.
2. Select SYSTEM.
3. Select ABOUT from the SYSTEM menu.
4. The software version is displayed with the title "Application" and 220.127.116.11.
5. If your Application is the same as listed in step 4 above, there is no need to download the software."
All it takes is an SD card Reader and a 32gig SD card... only takes a few minutes..
I really have been pleased with my HD-7... I was too cheap to go the side scan, I should have... it is a REALLY nice feature...