Three functional layers, with an optional second midlayer for colder or less active outings. The base layer sits against your skin and moves moisture. The midlayer insulates. The outer layer blocks wind, rain, snow and Zodiac spray. On top that means a merino or synthetic base, a fleece or light wool layer, an optional light puffy, then the parka or shell. On the bottom, thermal leggings, an optional insulating pant, then waterproof over-trousers.
The principle people miss is that layering works because you adjust before you are uncomfortable, not because more garments is better. Take a midlayer off before you start sweating on a hike. Put it back on before you get cold sitting in a Zodiac. Sweat inside your layers is what makes you cold later.
Keep the waterproof shell with you even on a clear morning. Conditions change fast, and the ride back to the ship is often wetter than the ride out.
Test the whole system at home, wearing the base layer under every planned midlayer and your waterproof pants. Sit, kneel, climb stairs, raise your arms. Anything that binds indoors will be worse in a Zodiac.