The actual drink "Coffka" was invented by the film's director, Glenn Allyn, while he was living on the west side of Chicago back in 2000, a year before he began working on the script. He found himself one night with only three options for drink: 1) tap water, 2) instant coffee, 3) and a bottle of Papov; and seeing as Option 1 was contaminated, and it was too late in the evening for Option 2, and Option 3 hurt on its own... Coffka was born (i.e., coffee and vodka).
Jayson Kochan, who plays the lead role of Clay, had just recovered from pneumonia a week before the Heaven's Shore scene was shot, where his character swims naked in the Northwest's Pacific Ocean during 45-degree weather and 50 mph winds. Unfortunately for Jayson, it took more than just a couple of takes.