1920 PORTLAND WARD 9, CUMBERLAND, MAINE U.S. MARINE HOSPITAL LARRABEE
Alfred H., age 38, patient, paper maker, paper mill, born ME both parents born ME he is shown as single so maybe he and Edith had divorced
U.S. Army, Register of Enlistments, 1798-1914 about Alfred H Larrabee Name: Alfred H Larrabee Birthyear: abt 1880 Birthplace: M'e Enlistment Age: 18 4/12
It shows he was born in Westbrook, Maine Year of enlistment in 1898 so perhaps he was on duty in Australia when he met and married Edith ?
Here is a marriage for him
New Hampshire, Marriage Records Index, 1637-1947 about Alfred H Larrabee Name: Alfred H Larrabee Marriage Date: 14 Jun 1920 Event Type: Marriage Marriage Place: Portsmouth, New Hampshire Birth Date: abt 1882 Age: 38 Gender: Male Father's Name: Alfred H Mother's name: Vernice True Spouse Name: Julia H Fickett Spouse Age: 36 Spouse Gender: Female Spouse Father's Name: Frank M Spouse Mother's Name: Charlotte Fickett FHL Film Number: 2069570
In image (at familysearch.org) this is listed as Alfred's third marriage and Julia's first. He is listed as a widower but if Edith had remarried that would be wrong. and another
New Hampshire, Marriage Records Index, 1637-1947 about Alfred H Larrabee Name: Alfred H Larrabee Marriage Date: 21 Dec 1901 Event Type: Marriage Marriage Place: Rochester, New Hampshire Birth Date: abt 1881 Age: 20 Gender: Male Father's Name: Alfred H Larrabee Mother's name: Bernice True Spouse Name: Mattie Hamilton Spouse Age: 17 Spouse Gender: Female Spouse Father's Name: Mellen R Hamilton Spouse Mother's Name: Mercy C Bond FHL Film Number: 2069570
Alfred's mother is shown as deceased ( you can see image of record at familysearch.org) His bride Mattie is shown as school girl !
1900 -9TH INFANTRY, PHILIPPINE ISLANDS, MILITARY AND NAVAL FORCES LARRABEE Alfred H., age 19, private, born Westbrook, Wisconsin
I think this is likely him and wrong state of birth as town of birth agrees with enlistment
So it looks like he was married once before marriage to Edith and once after.
1945 Florida State census LARRABEE Alfred H., age 63, retired, born Maine
Julia, age 60, housewife, born Florida
******************* I didn't find him in 1930 census either - I looked under his name and under Julia
I took a look at the passenger list you mentioned and I am sure they re your couple and they are going to Westbrook, Maine which matches with his home.