As investigations into paternal effects proliferate, empiricists are hampered by the potential effects of cryptic female choice and differential maternal effects. Ideally, studies of nongenetic paternal effects should exclude these confounding factors but such experiments are difficult in species with internal fertilisation. Species with external fertilisation, such as broadcast spawners, offer a highly tractable system for addressing paternal effects while precluding the maternal effects. Broadcast spawners reproduce by releasing gametes into the water column: this is the ancestral mode of reproduction and is the most common in the marine environment. Here, I will describe recent experiments investigating nongenetic paternal effects and epigenetic modifications of ejaculate in several phyla of broadcast spawning marine invertebrates.