My RS Vareo has a mainsail and the mast foot cannot be moved.
In strong winds (sailing upwind) the boat tends to turn windward. I kick the main sail and I hike. I keep course by slightly correcting with the tiller. Thus my constant small rudder correction likely slows the boat.
Is it normal? Should I sit further forward or back?
When a gust comes and I already kick and hike to the max, the normal counter procedure is to release the main sheet and let the sail fly a bit. I do this, but perhaps too late or too little. In order not to capsize or turning windward, I often find myself countering with the rudder so strong that I slow down nearly to a halt in that gust.
What am I doing wrong? Should I ease the sheet more and earlier? Sit further forward or back?
I think the hull shape makes the boat turn windward when heeling.
Thus I will try to slack the main sheet more or less constantly, even if the sail flutters, in order to keep the boat flat and upright.
Or what? :-)
 
Other dinghies have ways to reef the main sail, would be nice in this situation. But for RS Vareo you need to swtich to the separate optional Storm Sail. Perhaps I need to invest in one.
 
I am 184 cm / 83 kg. Have there been races in hard wind, when a skilled sailor of my size has chosen the Storm Sail and won against others using the full-size RAcing Sail? 

Hi Per,

sorry for the late answer.
I am also new to the Vareo and had the same problems in the beginning.
If wind increases (>3 Bft) and the boat starts to tilt to much and hiking does not help, you "lose" your rudder and the boat turns windward. As you said, the hull shape is one reason for that. If you want to maintain your course, you have to ease/release the main sheet, as you said. But you have to do this a little bit before a gust apears, because the boat reacts directly how you mentioned. You can also change the course by sailing more windward in a gust (if the gust does not change the wind direction to lee). This is also the way, the Vareo will "pull you naturaly". Often you will then only have pressure in the middle and the back of the sail, the front section shivers and won't give you much forcing. So, you are sailing too much windwards, but this prevents you from tilting too much and capsizing.
So you have to sail a little bit more visionary and react quikly ;)
If this situation appears too often, the sail is to big in my opinion ;)
 
I am around 190m and 77kg and have the competition and 2 months ago, I bought a used FUN sail.
The competition sail, I can only use in light winds (<3 Bft), it is too powerful/ too big and I am to light.
The FUN sail is ok until 4 Bft, but not optimal for high winds or when gusts appear. 
 
The FUN Sail has reef points, but they don't have a great effect, because the sail area is just reduce about 0,4m². That is not much. I thought about a second reef in the FUN sail, but then you have too much and too stiff unused sail area which has to be tied at the boom. Not really practical.
 
I have only heard positive reports about the STORM sail! It should have 7,2m². In comparison to the reefed FUN sail, it is just 0,4m² smaller. The cut should be flat. I think this is still too much for higher winds (>4-6 Bft). For example the LASER has 4,7m² in the smallest sail, as I know, and the hull weight is nearly the same. To your question concerning the storm sail: A new STORM sail is expensive (700€) and I couldn't find a used one. It might be a good investment to handle winds until 4 Bft with gusts, but please ask sailers who allready use it.
 
I will ask a sailmaker for an approximately 5,5m² flat dacron sail, semi battened. The pressure point of the sail will go more to the front. Will see what happens, I will tell you if it works :)
 
To sit more to the front is good, sailing upwind. The tail does not "adhere" to the water that much.
I couldn't find out an effect to the tilting problem (mentioned above), but if you look at some pictures from RS Vareo regattas, most people sit in the front when sailing upwind ;)
 
I am also in the beginning with the Vareo, but I hope that I could help you a little bit.
 
best regards
Jan