There you go calling it a track again,
It is usually called a headfoil or just foil. My Spanish extends to ordering drinks and finding the Bano so you are way ahead of me.
One more important point, head foils come in two sizes, general they take size #6 luff tape however on smaller boats such as a Merit they could have size #5 tape. If so, you need to buy a foil for # 5 tape.
#5 is not very common but if you are ordering on line I would find out for sure what luff tape you have, or if you can what your old foil is.
The Merit is a fun boat that sails well a buddy of mine used to race one.