Cooking and eating on a boat: the galley stove and its gas system, provisioning for a week at anchor, keeping food cold without shore power, and the grills, coolers and outdoor kit that make a boat day work.
Count meals, not kilograms. For a seven-day charter the crew usually eats ashore on the first and last nights, so plan five dinners aboard, six or seven lunches, seven breakfasts and two snacks per person per day. For six people that is about 30 dinner plates, 40 lunch plates, 42 breakfasts and 84 snacks. Then check the plan against the fridge, not the shopping trolley: a 12 V boat fridge of 80–130 litres holds roughly two days of fresh food for six, so anything perishable beyond day three has to be bought again or replaced with tins, jars, UHT and hard produce.
How much water per person per day on a boat?
Budget about 2 litres (0.5 US gal) of drinking water per person per day, rising to 3 litres in hot weather or with a lot of swimming and rowing, plus 5–10 litres for washing, cooking and dishes. For six people over seven days that is 84–126 litres to drink and 210–420 litres from the tanks. A 40–45 ft charter monohull typically carries 300–600 litres; a catamaran 600–1,000 litres. Most crews carry drinking water bottled and use the tanks only for washing, and with showers taken in the sea and rinsed with a hand-pump, a 400 litre tank lasts the week.
What food does not need refrigeration on a boat?
More than most people think. Unopened UHT milk, hard cheese in wax or a vinegar-dampened cloth, cured meats, butter in a cool locker for a few days, and any tin, jar or dried good. Onions, potatoes, carrots, garlic, cabbage, squash, apples, citrus and unripe tomatoes keep a week in a ventilated locker out of the sun. In much of Europe eggs are sold unrefrigerated and keep two to three weeks in a cool place; in the US they are washed and sold chilled, and the USDA advises keeping them refrigerated, so follow the local rule for the eggs you bought.