Need to waterproof mounted rebels

[stilettoman]

Hi all.  I want to build some lights for exterior and marine use.  Considered a cluster of 5mm's, but the comments here seem to tell me a Rebel or 3 would be the better choice.  Not trying to cast light, but I need high visability- 2 miles.  Colors are red and green.  Visability from all angles is important.  Longevity of the circuit is not an issue as the lights will be used for perhaps 4 hours per year.   I'm thinking of Epoxying the chips to an aluminum block/sink.  Power source is a 12V marine battery.  I could use a suggestion for a driver.

Questions: How do I waterproof the Rebel and mounting board?  What is the temperature at the surface of the LED? The thought was to coat the whole assembly with a marine epoxy. 

Is silver thermal epoxy significantly different than Amine based West System, or a polyester resin for heat transfer to the heat sink?

Would I be better with cheaper 5mm / 50 degree Leds angled to cover visablility from all angles.

Thanks

[minimum]

If you're going to use the Rebel, then Carclo has special side emitting optics:
http://carclo-optics.co.uk/catalog/product_info.php?cPath=116_23_32_104&products_id=180

Add aluminum heat sink, driver and cast in (low shrinking-) clear epoxy resin should work.