underwater machine

after wakeing up in a small cave seeing that wonderfull view i stood up and noticed a small light comeing from within a tunnel to my left. i starting walking towards it as i got closer i could here an odd sound like a train roaring down the tracks. as i enterd the room i saw the most wonder thing...... a machine that provides a shield type hul over the entire area. still no sign of life could this be a lost city????

seek part one of the underwater adventure to catch up on this if you are lost.