[Stealhead]

It is a Kilo.Hard to tell from such a grainy pic and the blocks are blocking the full view as well making it hard to tell if its more of a fin like bulge than a bulge and in either case we cant tell if it is like this on the other side.

Looks to me it may be a large bulge that is along the whole keel in that section of the boat and you cant see it all thanks to the blocks.Must be for some sort of SONAR would be my guess and a powerful one.Then again it looks as though might be some sort of thin tarp is laying over the hull see where the color gets more brownish in front of the conning tower looks like plastic maybe?Might be a tarp or some sort of cover and that bugle is the tarp hanging down at the bottom behind the blocks. Too hard to say from just this one photo.Though if it is a bulge it seems rather large and why in such an odd place? Looks like something for downwards scanning from its location.