ABANDONED. Houseboat with two children aboard caught in a storm in New England

[Laurie]

I have no title, no author. It's about a 9-yr girl who has led an unhappy life. She comes across a houseboat tied up at a river dock near her house. She goes aboard to explore and a storm comes on. She ends up getting trapped on the boat and falls asleep. During the storm a teenage boy also becomes stuck on the boat with her. He's running away from something/someone. He is carrying a little black and white kitty. The boat has loosened itself from it's tie-up at the dock and is headed downstream during the storm.The boy gets a bump on the head because of the boat tossing around and he is unconscious. She feasts canned goods on the boat. Their trip downstream takes maybe 2 days. The boy stays unconscious during the whole trip downstream. She comes to care for him very much during their journey even tho she knows little about him.
They wake up down near the NH/Maine coast. The boat has gotten stuck on an island. An local fisherman (his name might be something like 'Archie') comes out to explore and rescues them both. It's a fun story. I think the name of the book might be the name of the boat - Like Sea Witch (not correct) or else it's the young girl's name like 'Marnie". It would be considered a young adult book, I think. I read it in the late 70s or 80s. Does this bring any books to mind?
The story has a happy ending, but it's not all a bed of roses...there are rough spots throughout. A theme might be that all the characters find someone to love and someone who loves them. Also perseverance and loyalty.

[Rainbowheart]

Sounds a bit like The Little Ark, but that's set in Europe, not the USA.

[Rainbowheart]

Still looking, Laurie?

[Kris]

No response, moving to Abandoned folder.

Laurie (OP) was last active on the site in February 2020.