Baltimore’s waited decades for a swim like Harbor Splash. How did last time go?

For the first public swim in Baltimore’s Inner Harbor in more than four decades the water is expected to be more than 40 degrees warmer and appreciably more crowded than the last time around.

The Waterfront Partnership of Baltimore’s Harbor Splash on Sunday at Bond Street Wharf in Fells Point is believed to be the first public swimming event in the harbor since Jan. 1981, when Harborplace merchants organized what was envisioned as an annual winter swim to promote the then-half-year-old retail attraction.

According to coverage in the Baltimore Evening Sun, nine members of Boston’s legendary L Street Brownies swimming club — whose New Year’s Day plunge in Dorchester Bay, dating to the 19th century, endures — dipped into 38-degree water on Jan. 29, 1981. Deeming the harbor warm by their standards, the Evening Sun reported, the Brownies, some of them coated in baby oil, dipped to “a chorus of oohs and aahs from the small, bundled-up lunchtime crowd.” Part of the Polar Bear Weekend Festival, the swim was to be repeated the next day, and was hoped to encourage locals to join in the following year. However, it does not appear the event returned.

The 150 registrants of Sunday’s Harbor Splash can expect a water temperature around 80 degrees, according to the National Data Buoy Center.

While Harbor Splash participants must be at least 18, a century ago authorities largely had boys in mind when sanctioning five harbor swimming areas, located off Pier No. 8 on Pratt Street, the foot of Covington Street, the foot of Montgomery Street, Woodall Street Wharf and the B&O Coal Pier in Locust Point. According to an article in the July 9, 1925, Evening Sun, Baltimore Police directed men and boys to the controlled spots in the interest of safety —physical safety, at least, as water quality went unmentioned. The American Red Cross taught swimming and life saving at the sites with support from organizations like the YMCA, YWCA, Boy Scouts and swim clubs. Organizers set up ladders and lifebuoys and would even give swim trunks to boys who didn’t own a pair.

Have a story idea about Baltimore or Maryland history or a question that might lead to one? Email researcher Paul McCardell at pmccardell@baltsun.com.