When planning to come to Indonesia from the Gold Coast Australia, we purchased new sails from Evolution Sails Gold Coast.
We were told there would be little or no wind in Indonesia and therefore we invested in a large genoa, a large screecher and a large square top sail. Little did we know that this year was going to be different and we have had frequently winds of 30 -35 knots with a maximum of 52 knots recorded. This calls for some serious reefing and some of our friends have sent us questions regarding when we reef.
I actually have quite a serious alarm system : It’s called Ana – when the admiral yells she is uncomfortable I know it’s time to reef 😀
Usually we hear the term being quoted by sailors on catamarans : ‘Reef by the numbers’ i.e. we cannot feel the power on the boat so just do what the manufacturer handbook recommends.
I agree that one should be looking at the numbers but for us there is so much more to it so rather we use it as a guide more than an absolute.
At any rate, the numbers in our opinion are very conservative, in addition to a manufacturer sail size also being built to conservative dimensions.
On Impi we have a substantially larger genoa and main sail designed and manufactured along with a large screecher, Asymmetric and spinnaker sails. In spite of this we still have found in some conditions the numbers are conservative whereas in other conditions we would have to reef much sooner. The decision to reef is dependent on point of sail, sea conditions, boat weight and resistance on the helm.
Point of sail
We are more aware of the need to reef sooner on a close point of sail versus a broader point of sail.
In rough seas when sailing off one wave into the next the forces exerted by the resistance of the bows ploughing into a wave is significant. There are untold stresses exerted on the mast and shrouds, the support structure at the base of the mast and other parts of the boat through the wind power in the sail pushing a heavy vessel through the ocean, sometimes surfing the hull, in addition to the boat sailing into the back of a wave, the ‘stopping force’ of the craft versus the pushing force of the wind in the sail.
So for us it’s important to pay attention to when we need to reduce sail based on sea state and how well the boat copes with it. When we find ourselves ‘caught’ in sudden squalls we turn on the motors to help push the vessel through the water to ease the pressure on the sails by reducing the vessels resistance in the water.
Sometimes when stocking up the boat for long distance cruising we add weight through provisions like food, diesel etc. Sometimes we make water and fill the tanks to give the boat a fresh water rinse.
When the boat is heavily loaded the added resistance puts more force on the shrouds and other parts of the vessel along with the fact that our sails take more pressure so we take all that into consideration.
Resistance on the Helm
I can say that ultimately our big decider is resistance on the helm or the rudder angle in the water relative to the boats heading.
The boat should feel light and comfortable to maintain a heading without struggling for it. So from time to time I release the auto pilot and feel the helm and steer it for a while. Of course the rudder angle indicator is also telling, although there are times when you have a heavier helm like in currents.
The angle of the rudders in the water is a good indicator for us of being overpowered in what would otherwise be ‘neutral conditions’ : do we have a ‘heavy helm’ and would reefing or taking the pressure off the sails reduce it.
After trimming all the sails to get as close as possible to having the boat gliding along with little resistance to the helm we would reduce sail to see if it brings the rudders to a more neutral position.
We often find that by reducing sails the boat actually picks up speed, and a large part of that is because we are not dragging the rudders through the water at as much of an angle to maintain a heading.
On monohulls its quite easy because of the heeling motion of the boat but on multihulls rudder angle is quite a ‘tell tale’ we’ve found.