Polar Diagrams

Polar Diagrams are a graphical representation of the speed through water at various wind angles. They are very handy for planning your route as they will tell you (under ideal conditions) what speed you will make at varying wind angles. This will allow you to choose a route that is best suited to your yacht.

Polar chart of Wisdom. A full keel, cutter rigged, heavy displacement boat.

Now, a sloop with a very high-aspect ratio rig and keel will perform very well to windward. This will let you sail to a windward destination with ease and efficiency. In our case, the above polar diagram well demonstrates our performance statistics. 

As you can see, we do not sail well to windward, but we do sail quickly on a beam reach and down wind, but when we turn the wind forward of our beam, we instantly slow to a crawl.

After enough data collection, I was able to compile our own polar chart that will now help us choose a better weather route to our next destination. 

An important thing to note on a polar diagram, you will see that you will be able to point to windward, but you won't sail very fast. This means that you will not cover as many miles and you will get stuck somewhere as the weather changes over you. If you could choose a course that will have you sail faster, you will minimize the time of the voyage and allow you to get there in a quicker fashion. A quicker voyage means that the weather forecast won't expire before you get to your destination.

Synthetic Standing Rigging in the Cold

As the temperatures plummet, we have found ourselves trapped in cooler weather while we dream of warmer sailing. We have a few options ahead of us, one is to re-tension the rigging for the cold weather and sail along as normal; the other is to work with the slack rigging and make our way towards warmth as quickly as we can! 

If we were going to be doing high latitude cruising in the winter, then yes, re-tuning the rigging would be a wise choice to make as it will facilitate safe sailing with sound standing rigging. The thing is, we are heading towards warmer latitudes and if we tighten the rigging, we would immediately need to loosen it again as it would contract in the warmth. 

This leads us to our decision to follow the second option: deal with it. 

While the rigging is slack, the biggest concern comes in the form of shock loads. When you jibe accidentally, the loads are greatly increased because the sails slam from one side to the other and yank the rigging along the way. When the rigging is tight, the transfer of force is rather mundane, but when it is slack, the loads go from non-existent to out-of-this-world in a fraction of a second. This shock load can lead to a lot of gear failure and ruin a cruise! 

Dealing with it is rather simple. First, no accidental jibes. Second, don't fly much sail. The loads come from the sails being flown. If you fly small sails, then you won't be stressing the rigging very much. This means that we reef very early and usually sail under canvassed. Third, pick downwind courses.  

Sailing downwind is a great way to reduce the stress on the rigging. Everything moves along nicely as the backstays take up the majority of the loads. The apparent wind is also greatly reduced and you can sail towards your desitnation even faster than if you were beating with slack rigging. 

Running towards warmer weather will get you there in a short period of time, this means that soon, your rigging will warm up and you can stop worrying about it being slack as it will tighten back up on its own as it warms again. 

Our rigging is tuned for 80F, and works well all the way down to 60F. We have found ourselves lately in temperatures ranging from 40F to 50F, so we can't wait to be in warmer weather once more! 

Knowing Your Limits

Cruising might seem like fun and games. You get in your boat and sail to paradise. Everything is perfect and easy! Right? 

The truth is, cruising is a balancing act between what you can do and what you can't do. You will dance this line and occasionally cross it. When you do, you can either try and prove that the line doesn't apply to you or you can back off and retreat to your side of the line. 

Crossing the line momentarily may seem fun at times, but the punishment is always looming overhead. 

We have found that heaving to in a gale is a good method to survive the gale, but not a good method to enjoy a gale. Gales are much more enjoyable when experienced at anchor in a protected anchorage. The wind might seem "a bit stronger than usual" as the trees and landmass surrounding you shield you from the winds force.  The seaway is small, so there is no fetch for any waves to form and your anchor holds securely as you row to shore to enjoy a day in a new town. 

Likewise, we have also found that the ICW is best traveled downwind and downcurrent. The current in the ICW is a formidable force! We will frequently encounter currents in excess of 3 knots and if the current is working against you, you might find yourself moving backwards! 

While the current is strong, the wind is also a powerful player in this game. If the wind is on your nose and the current is pushing you, the windage of the yacht will cause you to slow to a stop as the current forces against your keel and pushes you along at a very slow pace. The danger here is that, while you are still moving at 2-3 knots, you are effectively motionless in the water and your rudder is not going to function properly. This means that you will have no steerage and will be at the complete mercy of the wind.  

We have tried to fight the wind and done stupid things like not use the motor and keep our sails down as we drift along with the current. The issue is the wind against the hull will drive you towards the banks of the channel and you will end up using all of your motor power just trying to keep in the deeper parts of the waterway. 

If the winds are very strong, you might find it impossible to motor against the wind, even if the tide is in your favor. These days are best spent at anchor where you can wait out the weather with a nice stroll through the local town. 

We have made it a rule that we will only venture out from our anchorage on days when there is no wind or the wind is behind us, and we will try to always go with the current.  

The wind is most important for us, being a sailboat. We can fly a lot of sail downwind and power against a weak current, but we can't seem to power against a strong wind! When the wind and current are in the same direction, and both pushing you, it may seem disheartening to find that the speed of the current will rob you of your true wind and your following apparent wind will feel very underwhelming. It is times like this that we have even opted to only fly the staysail, as the main just hangs limp and causes us to worry about an accidental jibe at any moment. 

With these simple rules, we stay well within the line of what nature allows of us while in the ICW. Wind and tide are formidable forces and fighting them will only remind you of the fact that you are a mere sailor and no match for such a force of nature. 

Tides and Currents

Tides are the rise and fall of water levels as dictated by the moon. High tide occurs every 12 hours and low tide also every 12 hours. The tide rises for 6 hours, then falls for 6 hours, over and over, every day for all time. 

The incoming tide is called a "Flood Tide" and the outgoing tide is called an "Ebb Tide". It makes since when you think about it because a floor tide will flood low level tidal land and when the tide recedes, it "ebbs" away. 

Tides are simple to comprehend as they are easily visible, but currents are what can be really fascinating! It may seem obvious that as the tide comes in, the current will also flow in and as the tide ebbs, the current also flows out. 

What might not seem too obvious at first is that at slack tide, when the high tide is at its highest and then begins to fall, the current can still be flowing! As the tide ebbs, the current can still be flooding! It is even possible for the current to never change direction as the tide floods and ebbs. This begs the question: How can water flow in while it is flowing out? 

Currents and tides may seem interlocked, but they are actually two separate animals. Tides are merely the height of the water level, and current is the flow of water. If you have a large river that drains into the ocean through a narrow inlet, the current may always flow out even with a strong tidal variance. Having more water present will cause the tide to climb, but the current can still flow regardless of water levels. 

When you are looking at waterways, it will be a huge help to learn the local water patterns. Look up tides and the currents in areas to see if you can figure out how they operate. If you can't get the information, it would be helpful to just anchor and observe it for a while. 

While transiting the ICW, we have encountered some very strong currents and we use them to help us travel south, towards our destination. The tides will rise and fall, but the currents seem to run on their own schedule, several hours delayed of the tide's shedule. By anchoring, we can visually see the intensity and direction of the tide by looking at the anchor rode.  

When the current is strong, it will actually form a wake behind the rode. When the current reverses, the boat will actually shift direction, letting us know the change has occurred. Writing down the times it changes is helpful as this lets you know when you will be traveling and makes sure you are prepared to leave when the tide will become in your favor. 

Once moving, looking at other stationary objects will help you determine the intensity and direction. The wake will always form on the downstream side of the object and the larger the wake, the stronger the current. Buoys will also tip over and create a wake when the current is strong!  

When the current is helping you, enjoy the bonus speed that it gives you. When the current is on your nose, drop anchor and wait for conditions to improve. Pushing along against the current is foolish when in a few hours, you will get a hefty push. 

If you are unfamiliar with how the local waters operate, simply ask a local fisherman and they will give you all the clues and know-how available to navigate the waters safely and easily. 

On a side note, flood and ebb tides are when water comes in or out. Slack tide is when the tide is at its peak or trough and the water level is not changing. With currents, you have the same setup, but the time with no current is called "Slack Water" and this is the time to navigate narrow or dangerous areas, as there will be no current pushing you into obstacles. Slack water only lasts around 15 minutes and occurs only 4 times a day, so if there is an area that requires slack water to pass through it, it will be imperative that you time it perfectly and don't be late!

Sailing in Currents

The idea of a 3 knot push might sound like a dream come true! People spend thousands of dollars to have feathering propellers and faired underbodies, all in the interest of gaining a few tenths of a knot, and here you can magically gain 3+ knots, for FREE!  

Currents are caused by the movement of water from one place to another, as the water flows, it will carry everything in it along for a ride. If you happen to be sailing in the same direction as the current, then you will get a nice push in the right direction! Your speed over ground will become your speed through the water + the speed of the current. If you are sailing against the current, your speed over ground will become your speed through the water - the speed of the current. 

It is important to know what direction the current is flowing that way you can use it to your advantage! 

Offshore, currents tend to move in a single direction at a fairly constant rate. They also tend to be well known, such as the Gulf Stream and its famed "counter currents" that run parallel to it on its bounderies. In shore, currents are typically caused by draining rivers or tidal waters ebbing and flooding. While the currents offshore all flow in the same direction, the currents inland tend to correspond with the tides and will alter direction throughout the day. 

Knowing when the current will be flowing and how strong can really help a vessel cover serious ground in a single day. We sailed across the Bogue Sound in about 3.5 hours, covering 24 miles at an average speed of 6.8 knots! We are by no means a fast boat, and we usually average less than 2 knots on a passage since we are dependent on the wind being in the right direction. This day was perfect, we were on a beam reach and had a very strong current pushing us along at over 3 knots! While our speed over ground may seem impressive, our speed through the water was our typical sailing speed of around 3-4 knots. By timing the tides and its current, we were swept into the Bogue Sound and reached its middle before slack tide. When slack water approached, we slowed to 3-4 knots since we no longer had the current helping us. As the tide began to ebb, we were swept out with it on the other side and sped across the remainder of the sound, reaching the other side by lunch. When we crossed the inlet, we were then faced with an opposite current as it was also draining into the inlet and our speed plummeted from 6 knots to 2 knots as we fought a 4 knot current on the nose.

Using these speed boosts can seem fun and will help you cover more ground with less effort, but it does take some precautions on the part of the captain. 

Bridges and other obstacles will approach at a much faster rate than you are used to. This means that you need to line up with the opening in the bridge perfectly well in advance, as the current will slam you into the abutments if you are trying to cut it close.  

Strong currents will also create eddies and vortexes that will swirl just behind large fixed objects. These swirling forces can pull you in and throw you off course. Your keel is especially susceptible to these phenomenon and will pull you along helplessly. 

Encountering other vessels is also tricky, as the typical rules about right of way are skewed to accommodate for the current. The vessel traveling downstream will have right of way over all vessels traveling upstream because the downstream vessel has less maneuverability. If you are approaching a bridge pass, the downstream vessel can not stop as the current will pull them through the pass, so the vessel traveling upstream must stop and wait; even if the downstream vessel is under power and the upstream vessel is under sail. 

Currents are fun, but they can be a little stressful in tight quarters where the speed takes away your ability to stop the vessel with the normal controls, such as heaving to or putting the motor in neutral. The current will carry you along and push you where it wants, and currents in narrow areas run faster as the water has to rush through the narrow opening in a hurry. This can add to the stress of the situation if not managed well. 

If you do not feel comfortable navigating with a strong current, you will be forced to wait for slack water to occur before transiting tight areas. While it might seem intimidating at first, an important thought to keep in mind is that anchors still work with currents. If you ever feel like a current is going to slam you into a bridge or wall, the anchor will hold the bottom and keep your yacht from traveling at the mercy of the current.