Warm, dry clothing
There’s a level of personal safety that I apply to both my crew and myself at all times and it’s doesn’t necessarily just involve carrying the latest bit of smart electronics in my pocket. Anyone who has spent a long night watch in foul weather and rough seas will know that the most important responsibility you have is to stay awake and alert. You are unlikely to do this when you’re shivering with cold and wet through. For this reason I put proper clothing as the number one on my list. Be prepared for all weathers and you’ll be able to concentrate far better on the task of keeping the boat on course and the crew safe.