I really don't think the rental and experience could have gone better. For several reasons. But basically, the problem was my (immediately clear) lack of experience and I was lucky enough to have made the booking with André.
André is patient, likes to teach, is a great communicator and story teller, and has life and nautical experience enough to share interesting stories for hours. And he is also an extremely nice person and business man.
The boat ride was amazing, we wen't to Seixal, practised docking and I learned in practice how things are done in the nautical world. it was a great experience, everything went perfectly well (with André's suggestions) and I look forward to renting with him again in the future.
I couldn't possibly recommend him more, even if he was my immediate family ;) Amazing. Thank you.
Keep up the good tourism work in Cascais.