In a blog post a couple of weeks ago, I mentioned trying to use a 100+ year old bridle on a single-line diamond kite and thereby turning it into a steerable dual-line kite. That did work, but there was still an issue with the kite losing its dihedral shape, caused by the spine no longer being connected to the flying lines.
I think I solved that issue by tying an extra Y-shaped bridle line from the existing single-line bridle to the two 'new' bridle lines, near the tow points.
Now of course, the ultimate test of their steerability is to fly a pair of them together. Now it so happens that the Vertex comes in three colour versions. The mostly green version is called 'Aurora', but there is also a mostly orange version which is called 'Infrared'. Green and orange are our often-used flying colours, so ..... You didn't really think we'd just get one of them, right? We're Flying Fish, remember? We fly kites in pairs ....
So the 'Infrared' Vertex was quickly equipped with the same extra Y-shaped bridle (we'd brought it with us to the field, in case it worked on the 'Aurora' one), and here they are, ready to go!