Basic Concepts and Techniques

Moderator: GreenLake

Sailing to and from a dock

Postby GreenLake » Thu Jul 09, 2020 5:12 am

There are many situations where you can sail directly from or back to the dock. Here's the basic technique:

docking.gif
Sailing to and from a dock
docking.gif (27.79 KiB) Viewed 260 times


Sailing from the dock: When you rig your boat, you have it pointed into the wind, so that the sails don't catch the wind until you are ready. With tiller fixed, sails raised, and centerboard down, you push off the dock with a bit of forward momentum so that there's flow over CB and rudder and you can steer away from the dock (or if the wind serves, just push the bow out). Sheet in, accelerate and you are off.

Sailing back to the dock: The trick here is that you need to slow down and take the wind out of the sails as you approach the dock. You may have to do a U-turn to do it. I've shown fenders out, but the older DS1s with their rub rail may not even need that, depending on the dock (at least not right away). You set up your approach so you can cost upwind with the sails slack. With a bit of practice you'll know how far you need to coast to slow down in the conditions. You can further slow down with rapid tiller movements, or even setting the tiller at full 90 degrees, or by sticking a paddle into the water and holding it still (the same paddle, or pumping the tiller, will work if your approach fell short).

The DS doesn't need all that much space for a U turn, so this technique works often even for docks that are at the end of a sort of cul-de-sac. If you need to make a U-turn right after leaving the dock, just make sure that you have good flow over centerboard and rudder blade and that you don't stall the rudder by giving too much tiller. If you stall your foils, you'll find yourself sailing sideways when that's not your intention (same if forget to drop your CB).

Other wind directions: If the wind isn't nicely parallel to the dock, that's usually not too much of a problem, as long as the wind isn't blowing directly onto the dock. If it blows away from the dock, you may have to rig your boat with only the bow tied on so it can weathervane, and sailing back to the dock you'll approach at right angles and perhaps also tie up only the bow until the sails are down.

If the wind blows squarely onto the dock, you may be able to still sail off (especially if the dock space isn't as tight as in the diagram, so you can sail parallel to the dock for a bit). However, there's no way you can set up to coast against the wind coming in. There are techniques that work, but they require knowing how to "heave to" (a useful concept in and of itself). Or you could drop your sails a bit further out and have the wind drift you to the dock (best with a paddle handy).

Finally, if you are in a place that has multiple parallel docks, you may be able to use a line and helpers to maneuver your boat in spaces that are too tight to sail out of. (Getting into such places sometimes just requires a bit of momentum)
~ green ~ lake ~ ~
GreenLake
 
Posts: 5562
Joined: Mon Jun 18, 2007 3:54 am

Heaving to

Postby GreenLake » Thu Jul 09, 2020 3:58 pm

Heaving to is a simple and very useful technique to "park" on the water. Being able to put your boat into the hove to state is an essential skill that allows you to stop actively sailing the boat, whether to take a brief rest, or to sort something out with the rigging. It can also be used in some other situations.

The basic idea is that you adjust sails and rudder in a way that they balance: the jib is backwinded to drive the boat down and the tiller is pushed to leeward to drive the boat up. The centerboard is down and provides the common pivot for both of these opposing rotations.

heaving-to.gif
Heaving to
heaving-to.gif (19.54 KiB) Viewed 257 times


The result is a stable balance with the boat drifting slowly downwind. The main is eased, but may be sheeted in a bit to control forward reach of the boat or help with balancing the jib (if the main is engaged it will tend to turn the boat more into the wind). The drift is slow and controlled, more forward than true downwind: The boat will lie at a-bout 60° off the wind.

Once the balance has been reached, the jib can be cleated, and the tiller lashed. The boat will remain in a stable attitude, even if the wind is gusty or oscillates. If the boat felt lively sailing upwind, you will be amazed how calm it feels when hove to. The boat will tend to itself: you can break out a snack; deal with anything you need both hands for; catch a needed breath or two; put in or take out a reef; or use the controlled drift to slowly move downwind. (The last can be useful in some circumstances: for example, in approaching a man or object overboard or in docking in a downwind direction).

How to heave to: The easiest way to heave to is to attempt a tack, but to not release the jib (so it ends up backwinded). As the boat turns, you put the tiller on the opposite side to stop and counteract the turn. You may find that it takes a bit of practice to prevent the boat from turning too far. If that happens, just release the jib and try again.

How to start sailing again: Just release the jib and sheet it in one the other side, sheet in the main and you are good.
~ green ~ lake ~ ~
GreenLake
 
Posts: 5562
Joined: Mon Jun 18, 2007 3:54 am

Controlled drift downwind

Postby GreenLake » Fri Jul 10, 2020 5:23 am

Here's how to use heaving to for controlled drift downwind.

We've seen that when you heave to the boat will drift at about 60° to the wind, that is, the wind and the drift angle will be a bit more forward than abeam. The reason that the boat doesn't simply drift downwind is that some small forward movement is required to keep the flow over both centerboard and rudder. Within some limits, you can adjust that drift angle by (slightly) sheeting in the main. Too much, and the boat will try to sail again.

Here's how you can use it to dock into a tight space when the wind is blowing towards the dock:

docking-downwind.gif
Docking downwind - controlled drift while hove to
docking-downwind.gif (18.32 KiB) Viewed 253 times


You find a spot at some distance from the dock and behind the spot you are aiming for. You sail a U ending with an upwind course from which you can heave to. Once you are hove to, you'll drift at about 1kn, very controlled towards your destination. You can use the main to change the drift direction to be a bit more forward.

It looks more complicated than it is, the main thing to practice is to find the correct location to start the maneuver, so you end up where you want to be. It may be easier to turn into the wind, backwind the jib and then let out the main and fall off slowly into the hove to position (arresting the turn with counter-rudder) rather than using the technique of leaving the jib sheet cleated on the "old" side while doing a tack. That latter approach is simpler if all you want to do is heaving to, but since it adds another 90 degree turn to the boat, it can make it that much harder to predict where you'll end up.

It's worth practicing this a bit - the same technique can be used to drift downwind towards someone you want to pick up out of the water. Again, the hardest part for that exercise is selecting and hitting the spot where to heave to.

Heaving to is an essential safety technique, that's why I think it belongs in basic concepts; and in many ways it is really more basic than many other modes of sailing - for example there's little need to be fussy about sail trim, and you can safely cleat the jib and lash the tiller, no fine tuning there either.
~ green ~ lake ~ ~
GreenLake
 
Posts: 5562
Joined: Mon Jun 18, 2007 3:54 am

Light Wind Sailing

Postby GreenLake » Thu Jul 16, 2020 6:26 pm

There are a couple of principles and techniques to get the best from sailing in light and very light winds. In no particular order:

Don't rock the boat: every time you move the flow over the hull and foils changes as does the airflow over the sails. In light and very light winds, it takes a while for this flow to be reestablished. You may also cause waves and eddies and any energy carried off by them has to come from whatever little boat speed you have. Sit still.

Keep tiller and sail trim steady: for the same reason, don't touch tiller or sail trim unless necessary. Keep tiller movements small. Using a tiller tamer or a bungee rigged to hold the tiller steady will work better than holding it in your hand. There's little "feel" from the tiller anyway and taking your hands off avoids any small involuntary movements. Instead, nudge the tiller every few minutes to keep on course.

Heel boat to leeward: doing so does two things. One, gravity will now swing the boom (and the sail surface) to leeward. This helps a very weak wind to "fill" the sails. Two, you will reduce the wetted surface of the boat (hatched in the picture below).

leeward-heel.gif
Heeling to leeward in light winds
leeward-heel.gif (11.35 KiB) Viewed 224 times


Reduce drag: at low boat speeds most of the drag is due to skin friction and is proportional to the surface under the waterline. At higher speeds most of the drag is due to generating a wave, and is influenced by the shape of the hull - so you want to sail the boat flat then, while at low speed, it helps to heel the boat.

Sail to the wind: when there's little wind, watch the water surface carefully for ripples (or darker patches) and, if possible, sail towards and in them, even if it means a bit of a detour. The shortest path may not be the fastest. On lakes, you may often find stronger winds near shore. (If you are out cruising and not racing, you may want to motor or paddle out of a calm spot)

Stick to your choice: it can be tempting to chase after fleeting patches of wind. Watch for areas of better wind and observe how they change. Are they stationary? Do they approach or recede? Will they still be there by the time you get there? Make your choice, but don't second guess yourself constantly - mid course changes will be slow.

Sail trim: in light winds, the wind is laminar, its speed and direction will change with height along the mast. Set your sails so they have twist. Jib fairleads back, vang off on the main, if you have a topping lift, use it to lift the boom a bit so it doesn't pull on the leech. In light winds, outhaul slack for a bit of belly in the sail, in very light winds, the sail needs to be flat again so the airflow can remain attached and doesn't separate.

Trim to the wind: when puffs alternate with calm, keep your sail trim to the expected wind, instead of trying to trim as you encounter the wind. Remember, it takes time for the airflow to establish itself. Set the course and sail trim for the direction you expect the wind from - which may not always be the direction the wind is shown at the masthead indicator! Blowing soap bubbles can be a fun way to "see" the direction of a very light wind.

Together, these techniques can get your DS moving even if it's hard to notice there is any wind at all, and you may have to watch some specks on the water to see that you are actually moving. On a day sail, this can be fun, almost meditative; in a race, it can make the difference between getting to the finish line or not in challenging conditions.
~ green ~ lake ~ ~
GreenLake
 
Posts: 5562
Joined: Mon Jun 18, 2007 3:54 am

Previous

Return to Seamanship and boat handling

Who is online

Users browsing this forum: No registered users and 1 guest