Student's Report:
Hello. We are Jason Chockley and Erik Davis.

Today's feature log entry is about life on the bridge. We have changed our rotating schedule to work with Dr. Baker and the PMEL scientists but first we wanted to share our experiences from the last three days with you. First of all when you are on the bridge and you look out across the deck and then past the waves and the horizon, you realize how small in comparison you really are. It's almost like our Florida Keys in that instead of an island, you are a ship "that is mostly sea and a sea that is mostly sky". The ship, the ocean, and the sky are all part of the command when you are on the bridge. On this cruise of the Ronald Brown you also have to be aware of what's below because that's what we are doing up here, keeping the ship in position while PMEL operations are taking place.

Before we left from Florida, we went through a three day training course at the STAR Maritime Officers Training Center in Dania Beach. We used their bridge simulator to prepare us and the practice paid off because we needed to know everything that they taught us for the last three days. Our bridge duty consisted of two, four hour watches a day. The first one went from 0800 until 1200. You always want to get to the bridge 30 minutes before your watch starts. This is because it usually takes a while before you get a feel for what is happening before you relieve the watchman before you. The second watch is from 2000 to 2400. All in all it was a pretty easy schedule and we learned a lot.

The first thing that we do when we relieve the watch is to make a weather report. They are made hourly and every six hours. The hourly reports include visual estimations of swell direction, height, cloud type and coverage. Real time measurements are also made of barometric pressure, temperature, time, GPS location and humidity using wet and dry thermometers. A six hour report is similar to the hourly one in that it includes an average of the hourly ones but adds wave fetch and period. The six-hour is then sent out to the NOAA center in codes, which is broadcasted along with reports from other ships in our area. It is very interesting because the NOAA Center sends us back a map that shows us where we are relative to the NOAA center as well as the other ships around us.

Some of our salty reefdogs described to you how the MTR buoys work a few days ago but we would like to tell you about how we maneuver the ship in order to pick them up. The ship can cruise forward and backward but sometimes we need to move laterally to port or starboard (it's called walking the ship). This is also a great feature to keep up lateral speed with the CTD while it's underwater or when we are docking. Well in order to walk the ship; we use the Z-drive thrusters. Two of the thrusters are in the stern and have regular propellers. The one in the bow runs by shooting a jet of sea water out in any direction. All of the engines and thrusters can rotate 360 degrees. We can control the thrusters with a joystick on the bridge where we can also tell the ship's angle and thruster velocity.

One of the many people that we worked with on the bridge was Merchant Marine Cadet, Jeffrey Lee. Jeff is from the island of Maui and is currently a senior in the Merchant Marine Academy in Kings Point, NY. He has been at sea now for several months and is very knowledgeable about navigation on the bridge. He taught us about calculating local apparent noon. Since we are about 260 miles out in the Pacific, we need to know where we are so we did that by 'shooting' the angle of the sun at a certain time at that latitude. We then plugged the data into an equation, worked it through the tables and bingo! We know the exact time the sun is directly overhead. That's important because now we can determine our GPS heading. Years ago when there were no GPS's; we used apparent noon to get our compass heading. By the way, we are now able to determine what time the sun sets or rises right there without listening to the evening news.

Another thing that Jeff taught us is calculating the error in the magnetic and gyrocompass. There is an error because the magnetic north is somewhere in Greenland right now and "true" north is at the North Pole of the planet. The further north you are, the greater the error. Where we are, there can be as much as a 20-degree error in the magnetic compass and almost 7 degrees in the gyrocompass. This makes a big difference when steering the ship over a thousand miles. The corrections are made after we have calculated the local apparent noon, which gave us our exact longitude and latitude. We then compared it to what the magnetic and gyrocompasses read and went down into the gyro compass room. This is where the sensors are located that give us our position. We then reset it to our local apparent noon calculations and record the differences between them. Yesterday we had an error on the gyrocompass of 1.2 degrees to the East. The magnetic compass had a 1.5 degree error to the East.

We see many things from the bridge. Several days ago a small school of common dolphin escorted us. We were excited to see them as they played in our bow and stern wake. Two days ago we saw two ocean sunfish (Mola mola) happily basking in the surface sunlight (until we disturbed them). The bridge has a night vision monocular. This instrument is really cool because it obviously let's you see at night. While nighttime operations are going on, we can see what's down in the water. Two nights ago, we saw plenty of the usual plankton jellies and squid but soon we started to see plenty of pacific scad. It was really fun watching them with the night vision but then suddenly a really big shark moved in and scared the scad away. We were fascinated by the shark and were amazed that it seemed that he wanted to come aboard with us. A marine biologist explained to us that it was probably attracted to some mild electric current in the ship. This really amazed us because we did not realize that sharks have electric sensors.

Well that's all for now. Tomorrow we will finish our story with more bridge tales from your Students at Sea.