I have found a website where you can see a product related to your inquiry. The link to visit is posted below. Based on the features presented, the POS integrates successfully for a shop that's main purpose is to sell scuba diving gear and any other related items.
Use the following link to reach the website: http://encompossoftware.com/scuba.html
You can also schedule a demo to see how things work before you get to anything serious like purchasing, payment, installation, etc.