Many people ask: What is and was the top speed for a large longship like the Sea Stallion and hence Skuldelev 2?
The answer is that we cannot as yet give the correct answer and it may be a long time before a reliable estimate can be made. This is particularly when we look at this top speed in relation to the ability of the ship to keep up a good average speed. That is to say a constant speed over long stretches and in relation to the wind speeds and wind direction. The ability of such ships to reach a high top speed is not always linked with its ability to keep up a good and stable average speed. It is this fact that is most interesting in the first instance, since it is what determined that longships like Skuldelev 2 and hence the Sea Stallion could be employed in practice.
With respect to the question of a stable speed, experience has so far shown that the Sea Stallion, when sailing at all angles to the wind, that is from a closehauled course, 60 degrees off the wind to a course on the run, with the wind from abaft, has exactly that extra reserve of surplus speed that is required, ½ to 1 knot (1 knot = 1.852 km.p.h). So much surplus speed gives for example 5-10 nautical miles (9-19 km) covered in the course of 10 hours. A good and stable fart is also an important safety factor, when long distances are to be covered by sea. The voyage to Dublin and the many data and observations collected on the way will help to give us a much better understanding of the speed potential.
The voyage out through Roskilde Fiord on Sunday 1st July with the wind from starboard, with the wind on the beam and on the starboard quarter did not invalidate our provisional impression that the ship had the ability to keep a stable speed in respect to wind speed and wind direction. The Sea Stallion trotted along with the usual characteristic undulations around the long hull. In contrast to the marked undulation followed by a trough in the waves and again followed by a marked stern wave occurring in the accompanying modern pleasure craft. The submersion and trim of the ship seemed to be in order.