Originally Posted by
WineCountryUA
"over water segment" is not the actual criteria used.
Actual rule, if any requested segment is BF or GF and no BF/GF clears, then the upgrade instrument (GPU or miles) should be returned, even if non-BF/GF segments cleared. RPUs do not have this exception and neither do itins that have no BF/GF requested segments.
In a large number of cases "over water segment" and BF/GF are the same but not all.
The only situation in which multiple segments have to clear in order for any of them to clear is if they are two segments using the same flight number (such as UA 803 that flies IAD-NRT and then also continues as UA 803 NRT to SIN). I don't think UA 49, BOM-EWR, goes anywhere beyond EWR.
WineCountry is correct about the difference between "over water" and BF/GF segments. If the BF/GF segment fails to clear, the GPU is returned after a few days to the account from which it came (in situations in which the GPU came from the account of a person other than the passenger).