After losing our rudder 800nm from land, we were in a siltation where we needed to make some changes to both the boat and our plotted course if the wanted to make it comfortably to St Lucia.
In our last post we talked about keeping the crew and boat safe in an emergency situation, now we need to address the issue of getting safely to land when we are still so far from shore.
We know the remaining rudder we have left is more effective with speed. This, coupled with the fact that the quicker we can get to land the less likely we are to encounter any further problems, means we need to keep the pace up. The problem with speed is that unless the boat is balanced properly, the load is too much on the rudder and we will wipe out.
Dagger boards
The dagger boards’ primary role on a multihull is to stop the vessel being pushed sideways through the water. Just like a keel on a yacht. Unlike a keel however, the best part about these boards is that you can lift them up out of the way when they are not needed thereby reducing drag and increasing speed.
Dagger boards on a multihull are especially good for keeping height while sailing upwind. In normal downwind sailing conditions they are not as critical as they end of being more drag. In our particular downwind situation however they were used for a slightly different role.
If you lose a rudder, like we did, the situation changes. We are now looking for ways in which to give the boat some extra grip in the water while sailing downwind. We had waves across the beam trying to push our transom away and rounding us up. This was causing the boat to wipe out with the boat rounding to windward and sails flapping. We used our dagger boards to our advantage here as extra grip in the water to help keep the boat bearing away. The rudder is still doing the steering job, the dagger boards just give the rudder something to turn around.
Sails
The next step to look at is our sails.
The ultimate aim is to try and take as much load off our remaining rudder as possible. In order to do this we need to look at how the sails in this situation are working and how best to balance the boat.
Reduce mainsail
We started with no mainsail and after some experimentation decided that our 4th reef worked great for us. For most cruising cats a 4th reef may not be an option so put the main away completely while you work on balancing the boat. What we were chasing is to have minimal sail area up aft of the mast to reduce the chance of rounding up.
The idea for Paikea was to have as much sail area up forward of the dagger boards as possible in order to pull us along down wind.
Forward sails
For sailing with only one rudder configuration, we ran our asymmetric fractional kite and J2 (otherwise known as a small jib) forward of the mast.
In this configuration we are generating most of the pulling power in front of the dagger boards. This means the sails are towing us down wind and keeping us bearing away. If we were to put too much sail area up aft of the dagger boards, we would find ourselves rounding up.
Making use of weather forecasts
We live in an age where we can access reliable weather predictions even when we are 800nm from land. We use IridiumGo to access PredictWind forecasts for our weather routing while on passage.
In order to successfully sail our catamaran to safety with only one rudder, we had two issues we needed to deal with.
The first was to try and get Paikea on a course where the waves were more aft of the boat. The current situation with waves on the beam was a major cause of wipe outs and slewing across the ocean. If we could work further north, we could then turn toward St Lucia and have the waves aft or behind us.
The second issue was that if we lost the remaining rudder, we needed to be in a position where we could drift towards our destination without drifting right past.
Using PredictWind enabled us to factor these concerns into our route planning. We also knew that there would be more rain cells developing closer to land and this too was something we needed to avoid.
Conclusions
So in summary, in order to sail our catamaran with only one rudder was not impossible. In fact, the trip was fine once we had sorted the three items mentioned above:
Dagger boards – we helped the remaining rudder by lowering dagger boards to give the rudder something to steer around.
Sails – we reused sail area aft of the mast and put up sails that would help drag the boat downwind.
Weather routing – we used PredictWind to plan a route where we would be in a position with more favourable wind and wave direction. We also made sure to give ourselves some added insurance and place Paikea in a position where is we lost the remaining rudder, we could drift towards our destination with no steering.
