Happened to mine, caught it just before it was another sacrifice to the wind gods.
My understanding is that the base is glued on after the internals are potted, so it is likely to drown, but if the bas comes off you could lose it, so I would try to force some epoxy glue into the crack and reinforce it. 
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It looks like that is the case as well in Boz's picture. 
Darn thing seems to have failed to record my session today too... 70+ kms up my shirt.
Select to expand quotechoco said..
Run a bead of silicone around it and should be fine
I ran a bead of silone around a repaired watch and it failed. If my mini-motion looks like that I reckon I'll try a trickle of super glue.
