The latest break-in interrupted a couple who thought they were alone. Investigators said it was caught on video.
The boat owners who captured that footage had just installed their surveillance cameras hours beforehand. The couple was fed up after they said things were stolen off their dock several times in recent days.
The video shows two men, who police said are in their 20s, getting onto a boat through a flap early Monday morning.
They were only on the boat a few seconds, trying to get into the main cabin area, where Dean Katsaros was sleeping. He said his dog started barking and was able to scare them off.
"Security leaves at 6 a.m. By 6:01, these guys jump on our boat and steal what they could. Fortunately, I installed a video cam last night. This was the first clip it took, which is ironic. It is what it is," Katsaros said.
Investigators said a few other boats in Diversey Harbor have also been burglarized in recent days. The boat owners said the thieves always strike on Mondays, between 4 and 8 a.m.
Anyone who recognizes the suspects should call police.