A version transcribed from the singing of Nic Jones. I expect he had it from a printed source:

My Willie sails on board a trader
And where to find him I do not know
Seven long years I've been constantly waiting
Since he crossed the bay of Biscay-O

One night as Mary she lay sleeping
A knock came to her bedroom door
Arise, arise my gentle Mary
And catch a glimpse of your Willie-O

So it's Mary rose, put on her clothing
And out of the bedroom then she did go
And there he saw her Willie standing
His two cheeks as white as snow

O Willie dear, where are those blushes
Those blushes you had so long ago?
O Mary dear, they are cold ashes
I am only the ghost of your Willie-O

And Mary dear, the dawn is breaking
Don't you think it's time for me to go
I must leave you here quite broken hearted
For to cross the bay of Biscay-o

Well if I had all the gold, the silver
And all of the money in Mexico
I would grant it all to the King of Erin
For to bring me back my Willie-O