I wish I could wear these on an actual boat

Yesterday after work I decided it was finally time for some retail therapy, considering the stressful several weeks I’ve been experiencing. I had been contemplating some boat shoes for awhile now and with the arrival of chillier weather (and my distaste for wearing sneakers outside of the gym) I decided some comfortable, non-fancy-flats were necessary and acceptable.

I am quite happy with my purchase of these Sperry Top-Siders but have only one issue; the shoes need to be worn in and stretched out a bit and fast, since they are rubbing my heels and giving me some little blisters. Any advice!?