Sealing holes below the water line

[Ski213]

Not where I'm running a fastener back in, holes left from abandoned transducer mountings, etc. I realize that maybe 5200 with the fastener back in is probably a permanent solution but I'm just curious what others do if the fastener is to be left out.  I'm talking 1/8" or so hole, not a hole you'd be left with after removing a thru hull transducer or anything.  What do you guys like for the job? 

[Crappiebasser]

5200 will fill a 1/8 hole easy without a screw in it.

[Avalonjohn44]

[Gundog]

Try this.....

 

[fishnkamp]

Marine Tex will solve the problem. Once it sets up you can lightly sand it and actually paint it to match the boat if you want.