I don't know if you have this. It doesn't answer your question but may help.
Canada Marriages 1661-1949 has:
Watson Frederick Porter, son of Bishop Porter and Clara ____,b abt 1879 Bridgewater age 23 m 15 Apr 1902 Riverdale, Nova Scotia Alma Phennela Mossman, dau of Simon Mossman and Martha, b abt 1879 Riverdale age 23
Nova Scotia Marriages 1763-1957 Vol 1829 pg 265 has:
Watson Frederick Porter m 1902 Lunenburg, Nova Scotia, Canada Alma Phennela Mossman