This looks like him travelling to Australia. he is alone so I am assuming he was single and married in Australia. It is noted on the original image that he is from Wales.
Name: William Walter PRITCHARD
Date of departure: 14 January 1921
Port of departure: London
Passenger destination port: Melbourne, Australia
Passenger destination: Melbourne, Australia
Date of Birth: 1898 (calculated from age)
Age: 23
Marital status:
Sex: Male
Occupation:
Passenger recorded on: Page 10 of 31
and this could be his death in Wales
Name: PRITCHARD, William W
Registration district: Conway
County: Caernarvonshire
Year of registration: 1967
Quarter of registration: Jan-Feb-Mar
Age at death:69
Volume no: 8A Page no: 162
It appears that they could have married in Wales when he came back in 1950. To find out whether or not they married each other and who her father was and her age you will need the marriage certificate.
Marriages Dec 1950 (>99%)
Pritchard William W Roberts Conway 8a 248
Roberts Margery PRITCHARD Conway Valley 8a 248