Whether you are plugged into the mains at a marina or running your engine to charge the boat battery at sea, your boat will be using energy, costing you money and producing emissions, such as carbon dioxide (CO2), that effect the environment.
There are a number of things you can do to reduce this impact without having to change much at all.
The temptation when down below is to turn on all the lights even if they are not really necessary. Make sure you keep you windows and hatches clean and free of salty residue to make the most of the light that does come in through them during the day. If you need a light then use one and make sure it is turned off afterwards. This will help towards saving precious battery power and in turn the fuel bills.
Wrap up warm and try to refrain from turning on the boats heating (if it has some). When on board the boat try and prevent getting cold in the first place by wearing suitable clothes and having enough extra layers to put on if it gets chilly. Check over the boat for drafts coming in through hatches or windows and fix any old or worn out seals to keep warmth in and water and cold drafts out.