The best system on the water for keeping dry and warm is the use of three layers.

Base Layers: Worn directly against the skin. Pulls moisture away from your body to keep skin dry while adding some insulation.

Mid-layers: These fleece or soft shell layers are worn on top of the base layer to provide a layer of insulation and also wick moisture away from your body.

Outer Shell: This keeps you dry and blocks the wind, generally a sailor's foul weather gear, but could be a windproof jacket on a dry day. It should also be breathable so that moisture from your body is transported out of the gear.