C-PAP keeps tripping GFI

[HandsFree]

Every time I plug my c-pap into the outlet in the forward birth on my 3700 the GFI trips.  I tried plugging in other thing and it is fine. I even tried all of the other outlets on the boat and every time I plug in the c-pap it trips the GFI. I am using a single 30 amp shore power cord and was thinking about trying the 50 amp cord to see if that makes  difference.  Any thoughts would be appreciated. 

Thanks
Dennis (aka sleepless in Michigan)