Thanks
@ginti, very helpful. I am indeed already checking ou Portofino Divers, who offer the full rental of the equipment. Happy to hear your positive experience. I am also looking into an alternative route in Belgium where I am looking for an instructor that could train us in the scuba dive pool over the winter. I found in Malta GozoTechnical diving, who do rec and tec from all major agencies. Malta is a nice diving area, and we went there twice in past.
If you have further personal recommendations, feel free to share (also via DM if that is more convenient). Since it is after all vacation diving, we can plan to go to any location in Europe.
In Malta, also have a look at Atlantis diving Center.
In France, cote d'azur, look for Plongeetec Marseille and Eau Blue Cavailaire.
In Sicily, Italy, Capo Murro Diving Center.
In Spain, Islas Hormigas Club de Buceo.
In Croatia, Krnica divers.
Not all of these diving Centres offer training from GUE, but you can arrange a course with external GUE instructors (Jerome Dechamps knows well both diving centres in France). Krnica... I think they only do GUE, but I am not sure 100%.
If you are interested in caverns, maybe you can try TheCaveToBe in the lot, but frankly speaking, I think it isn't worth a trip to that place just for cavern diving (for caves, it's amazing, but it's a higher level than yours). Malta would probably be a better choice.
If you want more info about GUE in Belgium, get in touch Diveolution in Leuven. They are just a shop (not a diving centre) and have bizarre opening times, so check in advance if you want to go there in person. But I would suggest an email before going there. Although they aren't a diving centre, both owners are GUE divers, and both are instructors, but only one teaches for GUE, Peter Brandt. Peter is really top-notch (massive experience in any environment, comparable to several instructor evaluators, although he teaches only fundamentals and DPV). However, he is extremely busy with his main job, so scheduling a course with him might be tough.
Jerome Dechamps, the GUE instructor I previously mentioned, is in the French part of Belgium. His English isn't the best (although he is capable of teaching in this language), but he is the most friendly guy I have ever met, an excellent diver, and he organizes dives every week, so if you want to find a group of likeminded divers, definitely send him a message (later on, you can always decide to go for other instructors). Again, he teaches for GUE and other agencies.
There are other Belgian divers you may want to contact here on this forum (if I recall correctly,
@beester and
@Miyaru are both Belgian tech instructors, although I do not know them personally).