President Biden Goes Shirtless for Another Delaware Beach Day

President Biden is all about the Vitamin D in the summertime -- as seen here ... where's losing his shirt and soaking up some rays in his native Delaware.

Joe was feeling sandy Sunday in Rehoboth Beach, where he's got a home. In photos obtained by TMZ, you can see POTUS and FLOTUS making their way out to the shore with a bunch of items in hand ... and a ton of Secret Service agents in tow, too.

JB was in his usual beach attire -- showing up with some trunks, a tee, and a ball cap. Eventually, he took off his top and went skins for the outing ... flaunting his gramps bod!

It looks like he was briefly out in the heat, but the plopped down in a chair to chill in the shade. Like we said, Jill was right next to him ... and they appeared preoccupied reading.

This is a pretty similar vibe to what they were doing a few weeks ago, right on the heels of the cocaine discovery ... which ended up going unsolved. You'll recall, at the time ... Joe was also doing some reading then -- and the missus could be seen throwing on some SPF.

No sign of any other family members here, including Hunter ... who continues to loom over the President's term. There's more that's expected to emerge in the coming days about Hunter -- including some potentially damaging testimony in Congress from an ex-biz partner.