Based on the variant "home and dried" and its origin in Australia in the early 20th century, it probably means being home and dried off and comfortable after doing something outside in wet and rainy conditions.
The OED says (under home adv):
Originally Australian. home and dry (also dried, hosed): having fully achieved one's objective; safe, out of danger.
Often followed by on the pig's back and variants (see pig n.1 Phrases P.16).
(Here, the OED tells us that "on the pig's back" means "in a fortunate or prosperous state"; I'll leave its etymology to another question).
It dates to early 20th century.
Early OED quotations include one from the London Times in 1917:
‘Are you British?’, he asked. ‘Yes’ was the answer... ‘Come on, Stewie’, he said to his mate. ‘We're home and dry.’
From 1918 in the Kia Ora Coo-ee, a magazine for ANZACs (Australian and New Zealand troops serving overseas, here in World War One):
All being home and dried, ‘Shorty’ went over to the ‘Q. Emma's’ to borrow a bit of ‘buckshee’ sugar.
And Australian novellist Vance Palmer in 1930:
You've done it this time, Lew! Home and dry on the pig's back!
The OED's alternatives "home and dried" and "home and hosed" suggest someone getting home and being dried off or cleaned up.
The OED's first citation for "home and hosed" is 1993, so it may be a later variant, and not a guide to the source of the expression. Max Cryer in ''Curious English Words and Phrases: The Truth Behind the Expressions We Use'' (2012) suggests "home and hosed" originated in horseracing, where a horse would be cleaned off with a hose after a race. The book also notes a change in meaning; originally it meant tired out and spent after a hard task completed; but now has lost the component of being tired out. But it appears far more recent than "home and dried/dry".
The fact that "home and dried" is about as old as "home and dry" suggests a common origin and meaning, of being home from the rain or work in the wet, and having dried off and being comfortable. No evidence it has a maritime origin; it more likely originates just from someone being out doing farm work or similar outdoor tasks (white Australians being better known for agriculture than seafaring).
(Unless otherwise noted, references are from OED online, accessed 13 September 2023.)