A “Yellow Submarine” was launched into the Flint River Wednesday morning—well, sort of.

It’s actually a sailboat that looks like the “Yellow Submarine” featured in the classic Beatles song, or a yellow banana, take your pick.

But for Matt and Sandee DeLapp of Buffalo, Wyo., it’s their new home.

The DeLapps, who are retired, have been working on their third boat, “Lollygag,” for the past two years. Last October, facing the prospect of blizzard weather in Wyoming, the DeLapps sold their home and made a 12-day journey to Bainbridge with their boat in tow. They were looking for a place with good weather and access to the Gulf of Mexico, where they hope to take “Lollygag,” and settled on Bainbridge.

“Bainbridge has been wonderful,” Mr. DeLapp said. “Everything felt right and people have been so helpful here.”

A small party of friends were at the Bainbridge Marina at around 10 a.m. Wednesday to help the DeLapps launch their boat.

Billy Birdsong, who manages the marina with his wife, Lynn, backed a trailer holding the boat down the marina’s ramp and into the Flint, with the help of a John Deere tractor whose bright yellow wheels matched the boat’s paint.

For the record, Mr. DeLapp said the reason the boat is yellow is to make it more visible to other boats, as it is only a few feet wide. Despite being narrow, the boat’s cabin is large enough to hold a queen-size bed, galley and other amenities the DeLapps will need in their new floating home.

Another advantage of the boat, which the DeLapps built from professionally designed plans, is its shallow draft of only about a foot. The boat’s two masts can easily be folded down by one person when not needed, useful since there’s just a crew of two.

For now, “Lollygag” is sitting in a boat slip, not far from where it was built at the marina these past few months. Although it floats and runs well with motor power, the DeLapps are going to put a few last finishing touches on it, including a bimini top over the stern.

Sometime soon, though, the DeLapps plan to explore the Flint and Apalachicola rivers before setting out into the Gulf, headed for the eastern Seaboard.

“Being retired, we just want to explore,” Mr. DeLapp said. “We’re basically chasing decent weather and going to places we haven’t seen before.”