I'm tryign to display the images on my product page as a vertical column down the page, which you can scroll down - like what happens in the Atlantic theme (https://themes.shopify.com/themes/atlantic/styles/modern/preview).
Is it possible to code this into the Debut theme? or somthing close?
The short answer is yes, that would be possible.
The longer answer is that whilst it is possible, it's something that you'll want to work with an expert to develop (unless you have the web dev skills in house). The forum can be handy for tips and such, but this would take more code editing than what you can reasonably expect here.
There's also the option of just using that theme. Changing themes for just one feature may be a crazy call to make so will leave that one with you.