Underwater leak repair

[rplank]

Can anyone recommend a product to plug an underwater leak? The base of the overflow partition is leaking over about a 4" span in my buddy's 120.

 

[MuralReef]

You might try this. I've used it in leaky bulkheads before but never underwater. According to the label it works though.
http://m.homedepot.com/p/J-B-Weld-Waterweld-8277/202528473/

 

[rplank]

Ok thanks!