Offshore sailing nutrition: high-calorie food for life at sea

Written by James Frost, founder of Flaming Phoenix and the maker of Phoenix Bars. Updated November 2026.

Quick answer: Offshore sailors typically burn 3,000 to 5,000 calories a day, more in cold, rough weather, so provision at least 3,000 to 4,000 calories per crew member per day. Keep a good share of it as no-cook food you can eat one-handed on watch, because the days when the galley is unusable are the days you need calories most.

In this guide

• Calorie needs offshore
• How much food to take on a passage
• Why calorie density matters on a boat
• What makes food practical at sea
• What food to take offshore
• How Phoenix Bars can be used
• Fuelling strategies by passage type
• Frequently asked questions

About this guide

This guide explains the specific nutrition challenges of offshore sailing, from weekend coastal passages to ocean crossings, and how to maintain calorie intake when cooking is impractical, storage is limited, and conditions make eating difficult.

For guidance on ocean rowing nutrition, see the Ocean Rowing Nutrition guide. For broader endurance nutrition principles, see the Ultra-Endurance and Expedition Nutrition Guide.

I make Phoenix Bars, high calorie bars built to fit as many calories as possible into a small, light bar, so I have an interest here; the advice applies whatever you carry.

Last reviewed: November 2026

Offshore sailing is physically and mentally demanding in ways that are easy to underestimate from shore. A crew member on a multi-day passage is working watch systems around the clock, grinding winches, handling sails, helming in rough seas, and living in a constantly moving environment where even basic tasks like making a cup of tea require bracing against the motion of the boat.

Calorie expenditure is high. Cold, wind, spray, and the constant physical effort of staying upright and functional on a heeling, pitching boat burn 3,000 to 5,000+ calories per day depending on conditions, watch length, and boat size. On a small yacht in rough weather, the number climbs higher.

At the same time, the conditions that increase calorie demand also make eating harder. Cooking in a galley on a heeling boat in rough seas is time-consuming, physically difficult, and sometimes dangerous. Seasickness suppresses appetite entirely. Fatigue from broken sleep on watch rotations reduces willingness to eat. Cold, wet conditions make hot meals feel essential but difficult to produce.

A calorie deficit builds over the course of a passage. Crew become progressively more tired, slower to react, more prone to poor decisions, and less able to handle the boat safely. Most experienced offshore sailors have seen the effect of under-fuelling on crew performance and morale, and the best skippers treat nutrition as a core part of passage planning.

How much food should you take on an offshore passage?

Work from 3,000 to 4,000 calories per crew member per day, then add a reserve of at least two or three days in case weather or a breakage slows you down. The table shows what that means for common passage lengths. Figures are approximate.

Days at sea are typical rather than fixed: a Biscay crossing can take three days or a week depending on the boat and the weather window, so plan on the slow side.

Why calorie density matters on a boat

Calorie density matters offshore for three reasons: storage space, preparation time, and the practical difficulty of eating in rough conditions.

Storage space is limited. Even on a well-equipped cruising yacht, food storage competes with sails, safety equipment, spare parts, water, and personal kit. On a racing yacht, every kilogram of provisions is a kilogram of displacement. Food that delivers more calories per kilogram means less volume in the lockers for the same calories, which is how our ranking of the best energy bars for expeditions orders them.

Galley time is limited. In rough conditions, cooking a proper meal can take 30 to 60 minutes of bracing against the boat's motion, heating a stove on gimbals, and trying not to scald yourself. On a short-handed boat with two people splitting watches, the off-watch crew need to sleep, not spend their rest time cooking. Ready-to-eat food that requires no preparation eliminates galley time entirely.

Eating in rough seas is hard. When the boat is heeling at 25 degrees and slamming into waves, sitting down with a plate and fork is impractical. Food that can be eaten one-handed, from a packet, while wedged into a cockpit seat or standing at the chart table, is far more likely to be consumed than a plated meal.

A standard sandwich delivers 300 to 400 calories but goes stale within a day and takes up significant locker space. A single Phoenix Bar carries up to 557 calories in only 120g, keeps for up to two years without refrigeration, and can be eaten one-handed on watch.

What makes food practical at sea

Offshore food needs to survive the marine environment and work within the constraints of life on a boat.

No refrigeration required. Fridge and freezer space on a yacht is minimal and power-hungry. Food that is shelf-stable at ambient temperature is far more practical than anything that needs to be kept cold. Phoenix Bars have a shelf life of up to two years and require no refrigeration.

Waterproof or water-resistant packaging. Spray, condensation, and the occasional wave in the cockpit mean everything gets damp. Food in packaging that survives moisture without the contents being ruined is essential.

Compact and stackable. Locker space on a boat is oddly shaped and limited. Food that packs flat, stacks neatly, and does not waste space with excessive packaging is far easier to stow.

Edible one-handed. When one hand is holding on, the other needs to manage food. Unwrap, eat, done. No plate, no cutlery, no preparation.

Does not create mess. Crumbs in a boat are a nuisance. Spilled food in a galley at 30 degrees of heel is a disaster. Food that is self-contained and does not require decanting, pouring, or assembly minimises mess.

Not excessively sweet. On a multi-day passage, palate fatigue from sweet snacks sets in quickly. Milder, more neutral flavours sustain appetite across days at sea when intensely sweet bars and gels become repulsive.

Mixes carbohydrate with fat and protein. Watch systems mean four to six hour blocks on deck, often through the night. Food combining carbohydrates, fat and protein is absorbed over a longer stretch than sugar alone, which suits a full watch.

What food should you take offshore?

Plan in three layers. For the first two or three days, pre-cooked one-pot meals such as chilli, curry or stew, frozen at home and reheated in a single pan, mean nobody has to cook properly while the crew finds its sea legs. After that, pasta, rice, couscous, tins, tortilla wraps, hard cheese, cured sausage and long-life milk carry most passages.

The third layer is the no-cook food for heavy weather and night watches: nuts, dried fruit, flapjack, oatcakes, chocolate in cooler waters, and calorie-dense bars. Stow a day of it within easy reach of the companionway.

How Phoenix Bars can be used

I make Phoenix Bars, so read this section with that in mind. On a boat, food needs to survive spray, salt air, locker compression, and weeks without refrigeration. Phoenix Bars have a shelf life of up to two years and take up minimal locker space; stow them in a dry bag like the rest of your food. They can be eaten one-handed in the cockpit during a watch, made into porridge in a mug with just water, or stowed permanently aboard as reserve nutrition. For single-handed or short-handed crews, every meal that does not require galley time is time that can be spent resting.

On watch. Break a bar into pieces and eat them through a watch. A full bar eaten across a four-hour night watch delivers up to 557 calories without needing to go below, use the galley, or take your eyes off the sea. Store pieces in a jacket pocket for easy access.

When cooking is impossible. In rough weather, when the galley is out of action and nobody wants to risk the stove, Phoenix Bars provide a calorie-dense meal-equivalent that is immediately available. Two bars (up to 1,114 calories) replace a hot meal's calorie content without any preparation.

As a meal with minimal effort. With just water, a Phoenix Bar porridge provides a meal of up to 557 calories in a mug in two minutes. No pots, no pans, no washing up, and the minimum possible galley time.

During seasickness. In the early days of a passage, seasickness can make eating impossible. As nausea subsides, small amounts of bland, calorie-dense food are often the first thing that can be tolerated. Small pieces of a Phoenix Bar, eaten slowly, can help get calories in as the nausea eases.

As permanent boat stores. The shelf life of up to two years means Phoenix Bars can be stowed aboard permanently as emergency or reserve nutrition. Keep a supply in a locker and rotate stock annually (Cherry Bakewell keeps for up to 12 months). If a passage takes longer than expected, weather forces a change of plan, or crew provisions run low, they are there.

"From my experience (having raced three times around the world, winning the BT Global Challenge and becoming the fifth British sailor in history to complete the Vendee Globe), I think these flapjacks are well-suited to challenging, long-distance water sports, such as offshore sailing."

"They've been particularly great when I've been seasick and they're all I can eat!! My team and I have ordered loads of these for our Atlantic row later this year!!"

Full nutritional information and ingredient lists for all six flavours are available on the product page.

Fuelling strategies by passage type

Coastal passage (1 to 3 days, harbours available). Provisions can be topped up ashore. Pack four to six Phoenix Bars per crew member for the trip as on-watch food and rough-weather backup. Supplement with fresh food bought in port. The bars cover the times when cooking is impractical or conditions prevent a proper stop.

Offshore passage (3 to 14 days, no resupply). This is where food planning matters. Pack two to four bars per crew member per day as on-watch food and no-cook backup, alongside hot meals from the galley on calmer days. For a two-person crew on a seven-day offshore passage, three bars each a day is 42 bars (about 5kg) and up to 23,394 calories of shelf-stable, no-cook food that does not need fridge space.

Ocean racing (fully crewed, high intensity). Racing crews need maximum calories with minimum weight and preparation time. Galley time is wasted racing time. Calorie-dense, ready-to-eat food that can be eaten on deck during a watch without going below is the priority, with freeze-dried meals for sit-down eating.

Single-handed or short-handed sailing. When you are the only crew, or one of two, galley time comes directly out of sleep time. Every meal that does not require cooking is time you can spend resting. No-cook food, including bars that mix with water into porridge, is particularly valuable for solo and short-handed sailors who cannot afford to lose rest time to food preparation.

Rallies and events. For organised rallies where socialising at stops is part of the experience but passages between are serious sailing, no-cook bars and snacks serve as reliable on-passage food that frees up galley time for cooking at anchor when conditions and company make it enjoyable.

Related guides

• Ocean Rowing Nutrition
• Ultra-Endurance and Expedition Nutrition Guide
• High Altitude Mountaineering Nutrition
• Hiking and Trekking Nutrition
• How To Use Phoenix Bars
• Calorie-Dense Foods: What They Are and When They Help
• Paddleboarding nutrition
• Offshore workers nutrition
• Sea kayaking nutrition

Frequently asked questions

How many calories do I need per day offshore?

Most offshore sailors burn 3,000 to 5,000+ calories per day depending on conditions, watch length, and physical demands. In heavy weather or cold conditions, the number is higher. Budget at least 3,000 calories per crew member per day of on-board food, with extra for rough weather days when hot cooking is impossible.

How many Phoenix Bars should I provision per person?

For on-watch food and no-cook backup, budget two to four bars per person per day, and more if you expect to do little galley cooking. For a seven-day passage, 14 to 28 bars per person (1.7 to 3.4kg) gives a solid no-cook base.

Do Phoenix Bars survive the marine environment?

They need no refrigeration and have a shelf life of up to two years (12 months for Cherry Bakewell), which suits permanent stowage aboard, kept in a dry bag. For heat and cold, customers report that they kept their shape even in desert temperatures on the Marathon des Sables and were easy to eat at -45°C on a South Pole expedition.

Can Phoenix Bars replace hot meals at sea?

A single Phoenix Bar delivers up to 557 calories, comparable to a hot meal. Made into porridge with water, it provides a calorie-dense meal in a mug with no galley cleanup. Pair it with hot meals on calmer days.

How do I keep food fresh on a yacht without a fridge?

Eat the fresh and chilled food first, in the first few days, and switch to tins, dry goods and long-life food after that. Keep fruit and vegetables in a ventilated net away from damp, and hard cheese and cured sausage wrapped in a cool locker low in the boat.

What should I eat when seasick?

As nausea subsides, small amounts of bland, calorie-dense food are usually the first things tolerated. Dry crackers, ginger biscuits and small pieces of a plain bar, eaten slowly, can help get calories in. Avoid rich, fatty, or strongly flavoured food until nausea has fully passed. Staying hydrated is the priority during active seasickness.

Buy Phoenix Bars

If you have any questions about using Phoenix Bars for offshore sailing, contact me directly. I am always happy to help.

James Frost

Founder, Flaming Phoenix

jfrost@flaming-phoenix.co.uk

07990 519422

Sources: Phoenix Bars nutrition and shelf-life values from our own pack labels; Customer reviews on flaming-phoenix.co.uk.