This was my first own design. It is made of Carrington and 2mm fibre-glass.
The wing span is 120cm.
Consult the plan for further details.
It flies surprisingly well, considering the high aspect ratio. I think this is because the wings have a "billowed" profile instead of being flat. Initially I used additional spars to obtain a fully tensioned sail, but this did not work very well: the kite flew but was very skittish with a tendency to nod or even completely flip over and nose dive. Removing these additional spars resulted in a much more stable, well-behaved flight. The billowing feature is now much like what you see on an Eddy kite.
The sea gull is probably most closely related to the Hewitt Flexkite (21K). The main difference is that the leading edge spar consists of 2 pieces joined by an eddy-style dihedral connector (fashioned from a bit of brass tubing). This is also very handy for stowing: none of the spars need to be removed; I simply extract the leading edge spars from the connector, roll up the kite and it fits in a neat little 60cm bag. Setup is a snap.
This seagull likes light to medium winds and the lightest line you can find. I fly it on 5kg line, but even this is really way too much.