I'm wondering what's the best way to fix a steel bracket to steel without welding and without drilling?

I want to attach some interior stuff in a narrowboat below the waterline. Obviously I don't want to drill a hole. I don't want something welded either because I'd need to take the boat out of the water.

The sides are a bit rusty but can be scraped to bare metal.

I imagine there is some kind of fancy epoxy that bonds steel to steel. Any suggestions/experience?

thanks

Robert