Hello! Thank you for asking on HCM! I read your question carefully and understand your concern. Scuba diving is a stressful activity for your body, but besides the physical activity, it imposes a severe pressure change to your anatomical structures, increasing even more the risk of bleeding from an aneurysm rupture. Taking ascal, may be safe for a normal situation, but may increase the risk of aneurysm rupture during scuba diving stress. There are not many studies related to scuba diving and aneurysms. Unruptured aneurysms, when in small diameters, have shown good results even when not treated with surgery (they have a low probability or bleeding, when unruptured). This is not a brain aneurysm, and I think that you can perform this activity with some restrictions regarding the depth of the diving, to avoid extreme pressure changes. (I would not recommend this activity in case of brain aneurysm, because the devastating consequences of possible intracranial hemorrhage). I recommend monitoring closely your blood pressure, before and after this activity and treat possible high blood pressure. Hope to have been of help! Greetings! Dr. Iliri