Wow, I am so sorry for you.
Between the Phantom, the Gimbal, the GoPro, and the fact that this is freshwater, it is DEFINITELY worth going to some trouble to retrieve....if it is at all possible. There are valuable, savageable parts and pieces of all three components.
What I am going to say next is not meant to be blaming or necessarily critical of you, while you're already bruised and hurting, and is meant more for the continuous daily influx of newbies on this site. What is different about the Phantom is that it is so appealing and ready-to-fly right out of the box that people with no or very little history or experience in the electronic R/C worldcan plunk down some (well, a LOT of) money and THINK they have something as solid and reliable as their new flat screen TV, their computer, their smart phone. Until very recently, and the Phantom specifically, the R/C copter world was almost exclusively Build It Yourself from kits and components, and moistly appealed to people moving from fixed-wing airplanes. Everybody with that background knew and KNOWS just how touchy and marginally dependable the hardware really is. NONE of this stuff is made with the quality control that would be demanded by Sony, Apple, Samsung, any of the major electronic importers. This is, so far, a small, niche market supplied by small, cottage industry, UN-supervised and UN-controlled manufacturing sites in China. The Chinese themselves AVOID buying this level of Chinese manufacturing in favor of spending more money (in China...since all products made for export are charged the export tariff even if they never leave the country) for higher level export-level items SINCE the big companies DEMAND better quality control and track this sort of thing carefully.
The statement made above that in the R/C world "you have to be prepared to lose everything on every single flight" is painfully very true. But for newbies seduced by the appeal, the out-of-the-box fly-ability, and whose dominant experience is with VERY RELIABLE big name imported electronics, many think these things are electronically as rock solid as their TV's and Iphones, and arejust as simple, intuitive, and built-in failsafe, meaning that reading manuals and tweaking and understanding complex issues isn't really necessary....the painful realities of this world all to often become apparent.
And here is my point, based on the above. My recommendation to EVERYONE is to proceed slowly up the learning slope with regard to risky flying. The issues are not just the newbies flying experience and ability....or lack thereof.....but the really UNTESTED electronic competence of about 100 (? or more) chips, components, solders, batteries, etc..
If, for the THIRD flight of a brand new bird, you had stayed over land.......you would NOT be out over $1000. That is the lesson for newbies. Stay OUT of risky environments until you have a large enough number of controlled and uneventful flights with each battery, new component/add-on, anything that changes/alters the bird. If one has 50 controlled, uneventful flights with a particular set-up (including THAT particular battery)....what are the chances that on the 51st flight something goes wrong and the bird suddenly comes down? Well, the risk is ALWAYS there, but the answer is....a LOT less than on the THIRD flight!
Luck plays a role in all this, but we can control a LOT of our exposure to the UN-controlled variable of luck. For myself, I have had some luck. I have had my bird for 5 months now, over 100 flights. I have had sudden power failure (from a loose-ish battery connector) that caused the bird to die, suddenly, 75 feet up. "Luckily" it happened over a solid grass field, no water within miles. But then, it also happened at a time when I felt NOWWHERE comfortable enough with the predictable reliability of the bird/transmitter/batteries/etc. that I was going to go out over an unforgiving environment.....and that was after about 30 flights, enough that the battery connector was getting looser. Later on I added a very temporary landing gear extension (steel coat hanger wire) attached next to the compass and WAS going to fly over water.....but LUCKILY the bird crashed before I ever got that far.....which drives home the point.
Yes, I now, carefully, put my bird out over water, deep canyons, rivers, etc.......sweating absolute nickels every second until it is back over land. But that is only with a set-up I know and have lots of experience with. New battery......don't trust it until I have a good history with it. Add a gimbal....attach a video TX.....do some soldering.....crack open the hood whereby I might loosen connectors to the Rx or NAZA.....don't trust it. New flying site.....DON"T TRUST IT!. Recent crash......don't trust it for awhile. Make some firmware alterations through the Assistant.....don't trust it. Basically, each and every new addition or alteration has to prove itself.....by repeated, controlled, no surpises flights....before I am going out over a non-forgiving environment.
I feel so sorry for you. I am saying this only so that other newbies in their earliest stages of flying (and in reality FLIGHT-TESTING) their new bird think about the conclusions I draw from your loss. These birds are NOT iphones in their electronic reliability. Failsafe and Return To Home (RTH) sequences probably, IMO, seduce people into thinking there is more safety backup built in than there REALLY is. How much more cautiously would people fly if there WERE no FS, RTH? I wouldn't be surprised if as many birds are lost because people make assumptions and take risks based upon a false sense of security in FS/RTH as those sequences really save. Don't get me wrong, I am glad they are there. But in 100+ flights....including flights over canyons, lakes, and rivers.....I have YET to experience or need them.
For me, that is a $1000 bill flying out there and I WANT IT BACK! Cautiously testing and proving the systems with boring repitition over safe environments seems a small price to pay. There IS no ultimate, absolute safety, but this seems to me the only way to reduce the risks to the lowest denominator of luck.....and still sweat nickels.
