This depends on where you are going. If you are travelling in an area relatively close to the shore, you can assume you will be picked up within 24 hours of an emergency at sea. In that case, the emergency pack would be overdoing it. However, if you are doing offshore sailing, then you should have an emergency pack with you. Another solution would be a “grab-bag”, i.e. a bag which can be grabbed quickly and which contains all the necessary emergency supplies.