Taken from Standard Horizon website:
Because the HX270S is built better, itís back better. If your Standard Horizon HX270S ever fails for any reason including water damage during normal use in the first three years, STANDARD HORIZON will repair or replace it free, without hassle or chargesÖperiod! If it fails thereafter in normal use it for the life time of the product it is covered by Standard Horizonís Lifetime Flat Rate Service Program.
So I would certainly contact them first.
Take my advice and never drink water . . . . I've seen what it does to the bottom of boats..