You gotta be kidding!...mask snorkel & fins are really cheap...do it yourself, then keep the gear on your boat...comes in handy sometimes.
The way to search in low to no vis is to drop a weighted line in the center of you search area then make circles. I would think that your search area will be a little larger than you think...a spinning prop wil have a trajectory from where it's shot off it's shaft. Never lost a prop, however, keys, tools, rod & reel, oh yeah! Good luck!