If you are careful follower on our Transatlantic paddler, you realized after speeding in the first week (daily average 40mi / 65km), last last 4 days was slower (daily average 27mi / 45km). The weather has not changed significantly, so I was wondering if this kind of slow down is normal for long distance paddlers.
To answer this question, let's take a closer look on "Crossing the Ditch" expedition. In 2007, James Castrission and Justin James crossed Tasman Sea in tandem kayak. During 62 days they did over 3300km(2100mi), what makes daily average 53km (33 mi). They were paddling in tandem boat which is definitely faster, but on the other hand they had rough sea conditions.
We also have to remember that real day distance is longer, comparing to straight line distance of locations taken for every midnight. I predict that extra mileage is about 20 per cent. So after short calculations current daily milleage for Aleksander is 32 miles / 55 km. This is nearly the same what we get for Crossing the Ditch challenge.
Conclusion: Current speed is natural for long distance ocean paddlers. It should be around 30 miles (50 km) per day.