A PT Eos/Vizz or BD Storm are great lights, losing one would not be good. OTOH, a cheap Walmart light may be better if losing one is likely. How about one good light for you and a couple cheaper lights for others and times around the river.

BTW, REI Outlet has the 2013 BD Storm on close-out at less than $40 -- good light at a good price. BD Storm is also IPX7. (no affiliation other than being an REI member since 1980-something)