The inevitable will happen one day.
Who do you ask?
UAVS is a good place to openly discuss all your options.
UAVS does specialise in the Ardupilot flight control firmware
but we also work on nearly every other type.
Feel free to make contact and ask your questions.
Depending on the frame, many upgrades can be performed on airframes to incease loads and flight time.
Be aware that this can be an exercise in dimishing returns unless you know all the inplications.
Upgrades can also mean better flight controllers with more functions/less restrictions and better stability and recovery.
Then there is upgrades of payloads.
What cameras can your frame carry, what cameras it can't.
Alternative payloads like dropping mechanism for payload delivery to name but one.
If you haven't had it happen to you then it is yet to come.
If you go up in the air then you have to expect a crash at some time either through machine failure or human error.
So it's happened and your wondering about your options.
UAVS is a good place to start.
Evaluation of damage is the first step.
Report on source and delivery times of parts.
Assistance in evaluating all the options for a speedy return to service.
If you have dumped your off the shelf drone in the sea, there is a good chance the only salvagable parts will be the motors and plastic bits.
But that might not always be the case.
Depending on the severity of wear or damage to your off the shelf drone, UAVS can provide costs and avalability of parts, repair time will always be dependant on parts shipping times from the makers, who are, unfortunately, mostly in China.
UAVS can clarify options and times and costs involved in these repairs.