They make directional feeder control units that you can hook up to most deer feeders. I just repurposed an old 300# deer feeder and put one of these on it. They had it in stock at my local feed store but I was able to find it online to show you what I'm talking about: https://westtexasfeedersupply.com/product/12-volt-directional-control-unit-wthe-timer/

this has a better picture of the top to show you how it works:
https://www.premierfeeders.com/west_texas_feeder_supply_directional_control_unit_58080_prd1.html

It throws pretty far, but you'd still need the feeder to be up on the edge of the water because some just drops straight down.

I didn't pay as much as that website is asking though, so you should check your local feed store see what they have or if they can get one. Might save you a bit.