Regarding the effect of the rudder on such a long hull, Could the fact that the scale weight of the hull is so much below what it should be if weight was directly divided by 96 then Steve's model would weigh 199.8 tons!

Now firstly, a model that heavy would sink on the given size of model straight away before we could even consider the rudder's effect on such mass in water, but as Steve's hull weighs a fraction of a percent of a ton then the rudder does not have so much mass to push around even when water (being the greater mass for given capacity) is taken into account for, the same for X1.

I am to maths what Kenny Everett was to particle physics but I think the light weight of Steve's hull might be beneficial for turning with a scale sized rudder.

A point I must make is that Steve's techniques of planking do give me confidence to have a go at a large hull in the future. Can you ask him to take some images of him painting the inside of the hull etc, as his method did surprise and again impress, as it is not what you would call classic model hull building, which is good for people who might be put off by the precise nature of wooden boat hulls.