Introduction
In this episode, we talk about sailing upwind in a catamaran. So why do catamarans have a reputation for sailing upwind so badly? Are daggerboards really necessary in order to reach some reasonable upwind angles?
The good news is for those of you sporting a breed of cat that doesn’t have a couple of daggerboards intruding into your living space you can still get your boat to go to windward. While daggerboards do provide some extra grip in the water compared to the keeled hulls of most charter variety catamarans, they are not the key secret to success. Let’s dive into what are the key critical ingredients to make a multihull successfully sail upwind.
The Headsail
The Sails
The most important ingredient for upwind performance are your working sails. That means, your mainsail and your headsail (or jib). Having the correct sail profiles are critical to upwind performance. This is why most racing boats will have sail stripes on their sails. Sail stripes help to visually identify the shape of your sail. On a catamaran, you are chasing relatively flat sails. The sail stripes will help you identify the fullness of your sail. You can use sail stripes on both the mainsail and headsail.
As certain sail clothes age and are used they will stretch and lose shape. This can impact drastically on your vessel’s performance.
The other aspect to consider is that forestay tension can also affect the shape of your headsail. The tighter the forestay tension, the more stable the sail shape will be. A loose forestay means that there will be more shape in your headsail depending if you are at the top of the wave or the bottom.
You can only sail as far upwind as your entry angle of the jib will let you. If your jib is too full, in other words your headsail has a lot of shape in it, you are never going to fill the sail correctly to be able to sail at 30 degrees apparent.
Sheeting Angles
The exit slot for the headsail is the space between the clew of the jib and the mainsail. This exit slot must be sheeted at the correct angle to allow maximum efficiency. We can reduce the exit slot gap on our headsail to improve our sail efficiency and sail closer upwind.
The Mainsail
We also use the speed stripes on our mainsail to help analyse shape and twist in the main. Along with these visual cues, we use specialized software to tell how full, or how flat, what the draft etc to give us additional data on our sails. You will notice that the sails on Paikea on quite flat, this shape is important to help us go upwind.
The Instruments
It is important to note that when sailing upwind, the Apparent Wind Speed or AWS will be more than the True Wind Speed or TWS. This means that your sails will be feeling more wind than is actually on the water.
Only 1 Rudder
Because we only have one rudder at the moment, we need to keep the speed up in order for it to be effective in the water. We drop the traveler to reduce the load on our remaining rudder which makes us go faster. Shayne also takes this opportunity to mumble about his traveler system again!!
Shaking out a Reef
Now we have more sail area at reef 3, we can go a bit faster. If we go too slow both our rudder and daggerboards are less effective. We try and keep Paikea sailing at 8kts upwind in order to balance the boat and keep the loads off the rudder. The extra bonus is that with the extra sail area we are able to keep the boat speeds
Mast Rotation
In order to increase upwind performance further, we can rotate our carbon wing mast. We can get a lot more height and speed when we rotate the mast. At this stage, we do not do this often as we don’t have a mast rotation sensor on the mast and it end up messing with all our instruments and data collection. We are still building polars and so need to make sure that the data we are collecting is as accurate as we can make it.
Want to learn more about jib trim on your catamaran? Check out this blog post on jib trim