I went to go fishing this morning and it appears that someone else needed my prop and everything else on the shaft. My question is, aside from the prop and nut, what other parts do I need to get water bound?
You'll need the thrust hub # 65758 ($18.99) which goes against the prop shaft before the prop goes on; you may also need a thrust hub # 62124A1 for the prop-nut end, depending on whether or not the replacement prop you get has a built-in thrust hub.
Unfortunately it seems that # 62124A1 is NLA (No Longer Available) from Mercury so you're either gonna have to find one used, or make sure you get a prop with integral hub so that it won't need this separate thrust hub.
Check out this diagram and you'll see the parts needed:
Here's a thought, the 700-3 had a similar lower unit to yours, but used a prop with integral hub and just had a locking tab under the prop nut. You might check to see if a prop from a 700-3 would work on your motor, and use the thrust hub and locking tab from that setup:
