you can also reach down quite a ways, maybe 5 or so meters at a rough guess. If jumping from a raised terrain, you are then able to recover stuff about 8m deep.
For deer ... learn the lesson (kill them on land) and let it go. There are too many deer for this to be worth recovering. Later if you must have that deer or whatnot, you can drag them back onto shore and into melee range with one of the weapons, but until then... let it go.