Upper Nile river Harpoon? Fishing spear?

[Shakethetrees]

Here's something I am, not to make a bad pun, "fishing" for information on.

The blade to socket length is 11 inches and a fraction long, asymmetrically forged, (obverse to reverse), and with a single barb.

The shaft is stepped where the line is secured. It appears to be hemp.

The shaft seems to be palm wood or something like it with a linear straight grain that is prone to splintering. The swollen grip is nicely sculpted with facets.

Overall it is about 52 inches long.

I think it is from the upper Nile river region because of the manner in which the point was forged.

Any comments or suggestions will be appreciated!