Approximately 2 years ago, I was driving thru Ina, Illinois, behind 4 eighteen wheel rigs, each measuring 75 feet long in or about the month of August on a foggy night when truck driver in front rig stated on CB, "in all my years I have heard about it but now I'm seeing it, is that a UFO?" "be careful looks like its coming down." As I Looked I saw UFO with lights all around it begin to descend and I asked "is there an airport?" Driver from 3rd rig responded, " I live around here and there is only a college and a prison and a lake." I observed object coming down and my rig started to tremble and I saw it very close to my rig since I was the last one in the caravan of rigs, I started honking at which time, UFO made a slight ascend to avoid hitting me and went right over my rig into a lake located off of Interstate 57, called "Rend Lake." I recall front rig driver saying "be careful whoever is in the back" At which point I saw the big disc star trek like object with lights all around it dive into Rend Lake making no noise and no splash when object went into water. My trailer shook and trembled and I felt it was going to tip over at which time I started honking to alert object and object missed hitting my trailer by small distance. I had no choice but to slow down instead of "stepping on it like front truck driver was screaming into the CB, as by the time the object reached us, I had no time to speed but slow down to avoid the object crashing into my truck. As flying object was coming down towards the lake, lights on object started going counterclockwise and spinning. I had to slow down from the then 55 mph limit to 20 miles mph in order to avoid space craft hitting my truck/rig. As a truck driver I noticed that in the summer, the green hides the lake and unless a person is familiar with the area there is no way of knowing Lake Rend is there, where I saw the Space craft go into the dark water lake. My heart was beating and I was racing with time in a truck/rig caravan as a truck driver where my only option was to slow down and honk at the space craft in order to avoid it hitting me since I was at the end of the truck/rig caravan. There is a rest area near this lake and I was traveling south when UFO object went into the lake on the opposite side of the interstate highway. There are two lakes there, one on each side of the highway and I lost sight of the object when it went into landed into the lake and disappeared into the Lake Rend.