When I saw this image, I realised why my mask had been leaking during that dive. The seal of the mask goes over my neoprene hood. I usually check if my mask sits properly on my face … actually I believe I did the check before that dive as well. It seems I was too fast and didn’t check the seal thoroughly. You know that saying “slow is smooth, smooth is fast”. It can be applied for this situation too. If I did the check slower I would have fixed the issue well before the dive … saving the time and making the diving more enjoyable.