So, as has been discussed, the trouble you may or may not have is not necessarily with the power requirement of the washing machine but it's electronics liking the waveform from the generator. The only way to test a washing machine on the output of your gennie is to come alongside a friends boat and power their machine through a cycle. You can then see what makes work with your set-up.
This is my experience on a Vetus (pah) generator, yours may well be different:
Zanussi Compact - Can be fussy, mine just twitched, that was an expensive lesson*
Candy Compact - Worked well but was too small
AEG - My present machine. Great but I need to put a additional electrical load on for it to kick into life....sometimes.
Miele are very well thought of but I can never square the cost.
* Expensive lesson in that manufacturers will not necessarily take back a machine that has been used... Of course how you check it works without running a wash I don't know. And then what excuse do you come up with when it works perfectly off shore-power but not off your generator on a boat?
There are other solutions get arounds to this common problem - like giving a feed of hot water to not use the heating element - or indeed going low tech and avoiding any of this nonsense...
Good luck.