We pulled up a muddy anchor this morning at seven o'clock.  By 7:30 we were waiting down stream of the 14 Mile Bridge for our second tow of the day already to come through first.  A half hour later we passed our third down bound tow.  It was a busy day of tow traffic as we passed several more without incident.  Just as we were approaching Three Rivers Lake, where we planned to anchor for the night there was an up bound tow and a down bound tow coming that we thought were planning to pass each other right there.  We mentioned this to "The Bar-B", but Bob thought both tows were ahead of us, so he slowed down.  We weren't sure until we saw the tow behind Bob, so we told him.  It turned into the joke of the night when Bob asked how we came to the conclusion that the tow was behind him.  Needless to say he sped it up a little bit.  This was our first time in this anchorage.  "The Bar-B" had been there on their maiden voyage, but could not remember it and said they did not take near as good of notes back then as they do now.  So we needled our way back along a narrow creek and went well beyond the 200 feet that was stated in the Skipper Bob Guidebook, but did not really find a comfortable spot.  In our time of idling around we noticed that the port engine was overheating, which has been giving us a little trouble, so we shut it off.  We finally dropped the anchor after deciding we didn't have much choice with no other anchorages close by other than just anchoring in the main Tombigbee channel.  Several small boats passed us with barely enough room once we were swinging around, so we asked them if there was actually a lake up in there farther.  They stated there was, but thought it was too shallow for us.  So Ray got in the dinghy and took our newly acquired portable depth finder to check it out.  Linda stayed behind just in case the boat ended up against the embankment or something.  Ray came back to inform us that there was nothing less than eight feet deep and knew where we needed to go as to not get into too shallow of water.  We cranked up the starboard engine, Ray pulled up the anchor, and Linda turned the boat around in the narrow channel on one engine as a first time experience.  We figured we might need to get used to it in order to make it the rest of the way to Demopolis.  When we got out into the "lake", it was much roomier and a lot more comfortable anchorage, making more sense as to the 12 boats the Skipper Bob Guidebook stated could fit in this anchorage and must have been misprinted and should have said to continue back 2000 feet.  The chart book and the chart plotter didn't look anything like the way the lake really was either, which didn't help.  We had dinner aboard "The Bar-B" and upon our return Ray decided to go ahead and check the impeller on the water pump and change the belt on the port engine to see if either of those might be the cause of our problem.