There are a lot of apps available for that. Search your app store for "phone tracking" or something similar. Many give you the ability to share your positions so you both can see each other live. You might even have an app already on your phone. For example, I have Lookout Security installed on my phone and it includes the ability to find the location of my phone from another phone or PC.
Watch your City Ordinances. Some city's require a back-flow preventor, and it can be VERY expensive.
I have both the battery backup, and the water driven sump pumps in my pit--all at different elevations, and feel very confident.
When the water comes up, and the power goes out, the battery backup starts working. After that the water driven sump pump will kick in. The water driven pump will keep pumping until the power is restored and the main pump returns everything to normal.
There is always water pressure in a power outage (from the tower). Cities keep the tower full for fire protection
VTX129 has a great point on nothing smaller than 9". I have a HB 998Ci HD unit. The bottom features that I can pick up are incredible- however I sometimes have a problem picking fish up on it. I have tried to keep my SI width narrower to help ID fish.
Overall fantastic tool. The hard to soft transitions are easy to see as are rocks and so forth.
On the HB units the larger screened ones come with the High Def transducer. The smaller units come with a compact transducer.
You can find some great prices on models that are being phased out - but they also will quit repairing those units sooner as well. Trade off's.
Check out Universal Mania and some others online for pricing.
Bass Boat central has a lot of info under Humminbird and Lawrance topics.