Prepare for the challenges you will meet on board!
During your shipboard experience, you will be able to explore the strange and wonderful world of plankton! In this station, you will toss a plankton net overboard and see what tiny plants and animals are floating around in the Chesapeake Bay. Then, you will make slides to examine these organisms up close under our video microscope.
Some facts you should know for the plankton station:
At the conclusion of this station, you will have a better understanding of the Chesapeake Bay food chain, and how to recognize and identify different planktonic organisms.
What would you say is the most important quality of a well-built boat? What keeps your body from sinking when you swim? What allows ducks to sit on top of the water? The answer to all of these questions is…. BUOYANCY!
The first thing to know about buoyancy is that it is a FORCE. What other forces do you know about? What is the force that pulls a ball down to the ground when you let it go? GRAVITY is a force that acts in a downward direction.
BUOYANCY is a force that acts opposite to gravity. It is the upward force exerted on a body placed in a liquid. In other words, buoyancy is what makes things float.
Do all substances float? What are some substances used to build boats? Do these float? How does shape and structure affect buoyancy? Is buoyancy important to the boat you will be sailing on? You will be able to answer these questions and more after participating in the BUOYANCY CHALLENGE during your shipboard adventure.
“The oyster is not a beautiful animal, except perhaps to another oyster, and, as a matter of fact, it does not even resemble a typical member of the animal kingdom. Yet this non-descript mass of protoplasm living between two calcareous shells has greatly influenced human civilization. Wars have been fought over the right to catch these animals, and many a man has met his death when he went to sea to retrieve them from the depths.” -Robert A. Hedeen, The Oyster: The Life and Lore of the Celebrated Bivalve
It is hard to imagine that this slimy, little blob of an animal could have such a tremendous impact on the Chesapeake Bay region. But the fact is, without oysters the Chesapeake Bay and its surroundings would be a very different place. Oysters are a “keystone” species in the environment, essential for the growth and development of other types of marine life. Many bay-side towns were literally built on piles of oyster shells. Last, but not least, skipjacks like our Sigsbee were built for the sole purpose of catching oysters! For this reason, we consider the oyster to be a very important little creature.
While on board, you will be able to examine live oysters, dissect them, and learn about this animal’s unique life cycle. In addition, we will examine how these animals affected the economy and history of the Chesapeake Bay.
With the wheel in your hand and the ship’s compass as your guide, you will actually steer the ship during your day of adventure! From this position onboard you will be in the unique position of determining where and how the boat goes.
It is important to know what to call the different parts of the boat when you are at the helm. The front of the boat is called the BOW. The back is called the STERN. When you are looking forward, the side on your left is called PORT and the side on your right is called STARBOARD. We use these terms on a boat to avoid confusion. You’ll also learn how to avoid ship traffic and submerged dangers, as you follow the navigation buoys in the water.
The water of the Chesapeake Bay is the element that shapes and determines the lives of many different plants and animals. Humans also depend on the water for food, recreation, and commerce. Without healthy water, the entire Chesapeake Bay ecosystem becomes endangered.
The Water Quality station gives you the ability to determine the health of the ecosystem by performing different tests on the water. You will become a research scientist and use chemical test kits to check the quality of the water. This data will tell you about the health of the water, and help you to determine what kinds of organisms may be living in it.
Some of the things you will be testing for include:
Temperature: the temperature of the water affects many of the chemical characteristics of the water as well as the species of fish and other marine animals that can survive in it.
Dissolved Oxygen: fish and other animals depend on the oxygen dissolved in the water to breathe.
pH: the amount of acid or base in the water.
Salinity: the amount of salt dissolved in the water.
Nitrates: the amount of chemicals in the water from fertilizers, decomposition, animal wastes, detergents, and organic matter.
It’s a fish, a crab, a jellyfish, and a tire?? Yes it could be all those things and more that you find in the trawl net during your trip. Your class will help the crew deploy and retrieve the net from the waters that we are sailing in. The luckiest member of your class will be very important to this process; it is their job to bless the net so we have a great catch.
You will have the chance to touch and hold the animals we catch while identifying what it is.
As part of the crew, you will learn how to find your way on the water. This is called navigation. While onboard, you will use your newly developed navigational skills to determine where we’re going and how to get there safely!
You will help to plot the ship’s course by learning how to read a nautical chart (a map of the water) and how to use different navigational tools. One important tool is the magnetic compass. Knowing how to read a compass is essential for navigating and for steering the boat. The compass is divided into 360 degrees and will show major directions such as North, South, East, and West. However, it is divided further and will also show the other 356 degrees, or directions, as well!
When steering the Lady Maryland, the helmsman is given a compass course by the watch officer. The helmsman will be given the course to steer in points. The 32 points of the compass are illustrated in this diagram. Each point is = 11 1/4 degrees. 11 1/4 x 32 = 360. Between every two respective points the compass card is divided into 1/4, 1/2 & 3/4 points.
What is mechanical advantage? If you look at each word separately, you can figure it out easily. “Mechanical” means having to do with machines.”Advantage” means benefit or gain. So, mechanical advantage means the benefit gained by using machines.
The boat’s engine is not the only form of mechanical advantage you will experience on your boat trip. You will use blocks (pulleys) and tackle (lines or rope). On traditional sailing vessels like Lady Maryland and Sigsbee, the crew uses halyards to raise the heavy sails. The halyard is a line that is run through two blocks to make raising them easier. You will be amazed how light the load will feel!
Other simple forms of Mechanical Advantage used in our daily lives include the inclined plane and lever. Examples of an inclined plane include ramps and screws and examples of a lever are a crowbar, oars, lacrosse stick, and a seesaw. Even the human arm can be used as a lever!
Dynamics of Sailing
A sailing craft exists in the world of wind and water – and a sailor knows these elements intimately. Using both wind and water, sailboats can move swiftly and silently over the Bay. Most forms of transportation use engines to overcome the elements, wind and gravity, while sailing works in harmony with these natural forces.
Students will help the crew of Living Classrooms Foundation’s sailing vessels with sailing operations and should try to understand the principles of how and why a boat sails.
Sailing downwind is easy, as the wind simply pushes the sails and boat along. However, when sailing upwind, there are a number of different factors involved. The most important is the shape of the sails. A sail is made to take an aerodynamic shape and forms a concave surface when filled with wind. The shape and function of a sail is similar to an airplane wing when examined in cross-section. A sail acts like a vertical airfoil (wing) that creates a force (lift) to propel the boat forward.
Actually, what happens is that the wind hits the leading edge of the sail and is forced to pass along either the front side or back side of the sail. However, the wind molecules don’t appreciate being split apart and they vow to meet again, reforming on the tailing (aft) edge of the sail. The wind molecules that go along the front are forced to travel further as they follow the sail’s bulging curve. The wind molecules traveling on the back side have a straight shot from the leading edge to the tail edge. The wind molecules on the front of the sail are spread thinly as they travel further and faster and the result is that they exert less pressure than their slow-moving counterparts on the aft face. The net result is the formation of relatively high pressure on the aft side (slow moving air molecules) and low pressure on the front side (fast moving air molecules). According to the laws of physics, air must move from an area of high pressure to an area of low pressure. This air flow creates a driving force that moves the sails and the boat forward and to the side. This side force (lateral slip) is reduced and somewhat transformed into forward movement by a long fin-like appendage under the boat called a “keel”. The keel keeps the boat from sliding sideways excessively. The rudder, another fin-like appendage under the water, is the steering device and which directs the boat’s course.
Tacking up Wind
While sailing it is very important to present the sails to the wind at a favorable angle. If a boat attempted to sail directly into the wind, the sails would luff (flap like a flag) and the boat would not more forward. Few boats can sail closer than 45 degrees from the direction of the wind. In order to proceed directly against the wind, the boat must tack back and forth, moving in a zig-zag pattern towards its destination.
When sailing, students will feel the normal heeling (leaning of the boat to one side) as the wind fills the sails. Tons of heavy lead weight called ballast are placed into the bilge (inside bottom of the ship) to give stability and restrain excessive heeling. Living Classrooms Foundation’s sailing vessels have been designed and built with great care and are superbly balanced.
Points of Sail
A boat can sail easily in most directions (the exception being directly into the wind). The Captain and crew adjust the sails according to the angle of the wind. If a boat is heading as close to the wind as possible (45 degrees), then the sails are pulled in close to the boat. This is called “close-hauled”. When sailing with the wind from behind, the boat is “running before the wind”, and the sails are let out far from the boat. Often the wind is “on the beam” (halfway between ahead and astern); at this time, logically, the sails are set halfway between close-hauled and running (this is called reaching). Therefore, a sailboat can maneuver in any direction by proper setting of the sails.
Knowledge of the dynamics involved with sailing is truly important, yet ineffective without smooth teamwork between Captain and crew. Cooperation and discipline contribute significantly to the efficient sailing of a vessel. With appropriate techniques and invaluable teamwork, a ship and her crew can meet the challenge of the sea while experiencing the exhilaration of sailing with the wind.