Most sailing trips never end with anyone in the water. A week on a charter yacht usually means sunburn, one overcooked pasta dinner and a lot of sitting in the cockpit with a drink. But the sea does not care about statistics, and the small events that actually happen on boats are rarely dramatic. A dinghy flips while you are landing on a beach. A wave comes over the side deck and finds the one locker you left open. A tender gets swamped on the way back from a restaurant at night. A bilge pump fails and a quiet inch of water rises under the saloon floor. 🌊
In every one of these moments the question is the same: what is still working five minutes later? The phone that guides you back, the passport that lets you board the flight home, the medication you cannot replace on a Sunday in a Croatian harbour, the handheld radio, the key to the rental car waiting in the marina car park. This guide walks through nine things worth waterproofing before you cast off, explains how to do it properly, and shows why a few small hard cases do a job that bags, pouches and good intentions often fail at.
A quick note on honesty before we start. A capsize in the strict sense, a boat turning turtle, is a dinghy and small-catamaran problem. A cruising keelboat is designed to stay upright and to right itself after a knockdown. Still, "capsize" is a useful way to think, because it forces you to plan for the worst-case wet day: everything in the boat is soaked, you are cold, tired and slightly stressed, and you need your essentials to be exactly where you left them. If your kit survives that scenario, it will survive the ordinary spray, rain and splash of a normal week as well.
Part 1: The Things You Cannot Replace Quickly
Start with the items that cost you the most time and money if they are lost or ruined. They are small, they are light, and they fit into hard cases the size of a paperback. That is exactly why they are the best place to start.
1. Your phone, the most important navigation instrument you did not buy for the boat 📱
On a modern sailing trip the phone is a chart plotter backup, a weather window, a camera, a translator, a payment card, a boarding pass and the only way to call your family. Salt water kills a phone in a way that fresh water often does not: the salt is conductive and it keeps corroding contacts after the device has dried out. A phone that has been dunked in the sea and "worked fine afterwards" can die two days later.
Many phones carry an IP68 rating, and that is a real strength, but it is tested in clean, still, fresh water at room temperature, not in a cold, salty, sloshing cockpit, and the seals age. Treat the rating as a safety margin, not as a plan. A transparent waterproof phone case lets you keep the screen visible and the device sealed during the moments when you are most likely to drop it: getting into the tender, climbing a ladder, handling a mooring line with one hand.
What to look for in a phone case for the sea:
- A proper gasket and a positive latch. A zip pouch is a pouch. A hard case with an O-ring seal and a latch you can feel click is a different class of protection.
- The right interior size. Phones keep growing. Measure the phone with its case on and check the internal dimensions of the box before you buy.
- Buoyancy. A lightly loaded small case often floats, and a case that floats can be fished out of the water. Do not assume this, though: weigh your loaded case and test it in a bath or a sink before the trip.
- A lanyard point. Clip it to a belt loop, a lifejacket D-ring or a bag strap, so that "dropped it" never turns into "lost it".
If you are curious how the IP67 rating on a Peli case actually works, our guide to what IP67 means for your Peli explains the test and its limits in plain language.
2. Passports, boarding passes and the ship's papers 🛂
The documents on a sailing trip are not just yours. On a charter you may carry the skipper's licence, the charter contract, the boat's registration and insurance papers, the crew list and, in some countries, a radio licence or certificate. Port police and coast guards in several Mediterranean countries do ask to see these, and the officer will not be sympathetic if they have turned into pulp.
Paper is the weakest link in a wet environment. Even a plastic sleeve leaks at the edges after a few weeks of being squeezed in and out of a bag. A shallow hard case with a seal is a much better place for the passport and ID cards, the printed booking and insurance papers, a small amount of cash and your bank cards. Keep a second set of copies elsewhere on the boat, and a photo of each document in cloud storage, but make the originals as safe as you can.
A practical rule that works well on crewed boats: one document case per person, and it lives in the same place on the boat every day. Choose a locker that is high, dry and easy to reach, and tell everybody where it is. If you ever need to leave the boat in a hurry, nobody should have to guess.
3. Keys, key fobs and the car that waits for you 🔑
Modern car keys are small computers. A key fob that has been soaked in salt water can stop working, and a replacement key for a rental car in a foreign country is an afternoon of phone calls and a few hundred euros. Your boat keys, the marina gate card and the locker key are a close second: marinas tend to charge a deposit for a lost electronic card, and a lost gate card at midnight means waiting for the harbour office to open.
The smallest hard cases, the kind made for keys and cards, are perfect here. They fit in a pocket, they seal against water and they stop keys from scratching a phone screen. It is a modest purchase that quietly prevents the single most common "stupid" loss on a boat trip. If your key fob is bigger than usual, check the interior length before you order.
4. The handheld VHF, the personal locator beacon and anything that talks to rescuers 📻
This is the one item on the list where the choice of container can matter for safety. A handheld VHF radio is a lifeline on small boats and tenders where the fixed set is out of reach. A modern handheld with built-in GPS and digital selective calling can send a distress alert with your position. A personal locator beacon, a PLB working on the 406 MHz frequency, is a separate, independent device that must be registered with the relevant national authority before use. Check the registration and the battery expiry date before every season.
Many of these devices are designed to be water-resistant or even waterproof on their own, and you should read the manual rather than assume. What a case adds is protection against impact and against the slow damage of salt, sand and sunscreen in the bottom of a bag. It also adds one very practical advantage: a case with a clear, repeatable place on the boat makes the radio easy to find in a stressful moment.
Two rules we would never skip. First, never seal a device in a way that blocks its operation or its antenna during an emergency; keep the radio ready to use, in a pocket or clipped to your lifejacket if the manual recommends it. Second, the case is storage, not a replacement for the lifejacket, the tether or the training. A radio you have never practised with is a very expensive paperweight.
Grab & go: small cases for phones, keys and papers 🔑
Part 2: The Things That Keep You Healthy, Informed and Entertained
The second group is bigger and less urgent, but it decides whether a wet day is an anecdote or a ruined holiday. Here you move from pocket-size cases to boxes that can hold a first aid kit, a camera or a tablet.
5. Medication and the first aid kit 💊
Think about the medicines that cannot be replaced easily: prescription drugs, an inhaler, an EpiPen, insulin supplies, seasickness tablets that work for you and nothing else. A pharmacy in a small Greek or Croatian harbour will be closed in the afternoon, shut on Sundays and may not stock your brand at all. Humidity ruins tablets in blister packs faster than most people expect; a bag of damp painkillers is common in the bottom of a sailor's locker.
A hard case with a gasket is a good home for a personal medicine kit. It keeps the contents dry, it protects fragile items such as glass ampoules and pen injectors from knocks, and it can be marked clearly with a red cross so that anyone on board can find it. Some medicines are sensitive to heat: a locker in direct sun in July can reach temperatures that are bad for insulin and some other drugs. Read the storage instructions and use an insulated option where needed, because waterproof is not the same as temperature-controlled.
Keep a printed list of your medicines and doses inside the case, in English. If you need to see a doctor abroad, it saves a conversation that neither of you will enjoy.
6. Cameras, action cams and the memories you cannot reshoot 📷
A week on the water is full of photos you cannot repeat: the sunrise over an anchorage, children jumping off the bow, the first time someone steers. Cameras and lenses are exactly the type of equipment that fails in a spectacular and expensive way when exposed to salt spray. Salt crystals on a lens are abrasive; a quick wipe with a dry cloth scratches the coating.
The practical answer is a medium hard case with foam or dividers, kept in a dry locker, and used as the camera's home between shots. A good case does two jobs: it protects against a sudden swamping and it keeps the daily salty air away from the glass. Add a few silica gel packets, replace them regularly and open the case once in a while in a dry cabin to let it breathe, because a sealed box can trap moisture that was already inside it. Peli Protector cases include a pressure equalisation valve for exactly that reason: it lets the case adjust to changes in altitude and temperature without forcing water past the seal.
Also back up your photos every evening. A memory card in a case is safe; a memory card in a case and a copy on a phone in a different case is safer. A single point of failure is the real risk, not the sea.
7. Power: batteries, power banks, cables and chargers 🔋
A boat is a surprisingly hard place to keep devices charged. The 12 V socket works only if the engine is running or the service battery is healthy, and a USB port is often shared by five people. Power banks become precious. They are also the one piece of kit airlines care a lot about: lithium batteries must be carried in the cabin, not in checked luggage. Our guide to power banks in carry-on baggage explains the rules and limits in detail, so you can plan both ends of the journey.
On the boat, treat lithium batteries with respect. Keep them out of direct sun and away from the engine compartment, never charge them unattended in a closed locker and never use a swollen or damaged cell. A hard case provides an additional layer of impact protection and, if a battery ever does fail, it is much better stored in a rigid container than loose in a bag with a lighter and a sunscreen bottle. Do not seal a charging battery inside a closed case; remove it from the case while it is charging.
Put cables, a small multi-port charger and one or two spare adapters in the same case as the power bank, so you do not have to dig through five bags to find the one lead you need.
8. Flares, signals and the "if all else fails" kit 🚨
Distress signals have expiry dates, and many charter yachts carry flares that are close to the end of their life. Pyrotechnics are regulated: how you store, carry and dispose of them depends on the country and the type, and in many places the expired ones must be returned to an authorised collection point, not thrown in a bin or the sea. Always follow the manufacturer's instructions and local law on storage and handling.
What a hard case is good for is the rest of the signalling kit: a whistle, a signalling mirror, a waterproof torch, spare batteries, a small laminated card with the boat's name, position format and emergency numbers, a spare lanyard and a handful of cable ties. These are the small things that tend to vanish into the bottom of a cockpit locker. A bright, easy-to-spot case marked "EMERGENCY" lives near the companionway and gives everybody on the boat the same expectation: this is where it is, and this is what is inside.
Make it a habit to read the contents aloud on the first evening of the trip. Nobody will remember the list during a real emergency, but they will remember doing it.
9. Tablets, e-readers and the passage-planning backup 🧭
Even on a boat with a chart plotter, many skippers keep a tablet with a second chart application, tide tables, pilot books and weather. It is a cheap and sensible redundancy. It is also a large flat screen that does not enjoy being sat on, rained on or dropped on a teak deck. An e-reader for the evening watch or a kids' tablet for a rainy day has the same problem.
A medium protective case fits most tablets with room for a charger and a pair of earphones, and it travels well: it fits under a bunk, in a locker or in the overhead bin on the flight home. The trick is to size the case before you buy it. Measure the tablet with its protective cover on, add a centimetre of margin on each side for foam or dividers, and check the inner dimensions of the case, not the outer ones.
Bigger boxes: first aid, cameras, tablets and the emergency kit ⛵
How to Waterproof Properly: A Checklist for Departure Day
Owning the right cases is half the job. The other half is how you use them, and the mistakes people make are surprisingly consistent. Work through this list on the first morning of the trip, ideally before the boat leaves the pontoon.
- Test the seal at home. Close the empty case, put a sheet of dry paper inside and hold it under water in a sink or bath for a minute. If the paper stays dry, the gasket works. Do this once at home, not in a storm.
- Check the O-ring. Look for grit, hair, sand and dried salt on the gasket and the groove. A single grain of sand can break a seal. Wipe with a clean, damp cloth and, if needed, a thin film of silicone-based grease as the manufacturer recommends.
- Close it dry. Close the case in a dry place. If you seal it while the contents are wet or the air is damp, you trap that humidity inside, and it will condense on the first cold night.
- Latch every latch. A case with one latch open is a case with no waterproofing. Run your thumb along every latch before you stow it.
- Mind the pressure valve. If your case has a purge valve, leave it in the position the manufacturer recommends. It exists to equalise pressure, and it is an intentional part of the seal, not a leak.
- Weigh and float-test. A loaded case can sink. Test the combinations you plan to travel with, and if a case sinks, attach a small float or a lanyard to a fixed point.
- Label and place. Use a bold label on the lid. Decide on a fixed place for every case, and tell the crew.
- Rinse after each trip. Fresh-water rinse, dry, then store open. Salt is the long-term enemy, not water.
- Inspect parts once a year. Latches, handles and O-rings are replaceable parts. If you ever need a spare, it is a simple and cheap fix.
Dry Bag, Hard Case or Both?
This question comes up in every conversation about waterproofing, and the honest answer is that they do different jobs. A roll-top dry bag is light, cheap, flexible and good for clothes, towels and sleeping bags. A hard case is rigid, protects against impact and is ideal for fragile or valuable items that need to keep their shape. Most sailors end up with both: bags for soft goods, cases for hard goods. We compared the two in detail in Waterproof Case or Dry Bag? 9 Situations, and that article is a good companion to this one.
If your trip involves paddling as well as sailing, for example a tender, a kayak or a stand-up paddleboard, two other guides are worth reading: SUP board gear: 9 things that break, get wet or sink and the kayak packing list. Both cover items that overlap with the nine above, from phones to keys.
And if the trip is built around diving, the dive trip packing list and guide deals with the equipment that spends more time wet than dry.
Three Real-World Scenarios Worth Rehearsing
The swamped tender
You are returning from a beach restaurant at night, five people in a four-person inflatable. A wave breaks over the bow, the outboard stalls and everybody is soaked to the waist. What is in your pockets? A phone in a sealed case, a key in a micro case and a torch on a lanyard mean you can call the boat, get back on board and carry on. Without them, you are phoning from a stranger's phone or paddling in the dark.
The open locker
You leave the cockpit locker unlatched, a wave comes over the side deck on a beam reach, and a few litres of sea water pour in. Everything on the bottom shelf is wet. Papers, snacks, spare clothes, the charger bag. Cases on the shelf survive, and the damage is limited to a good rinse and a bad mood.
The slow leak
The rarest scenario and the one people forget: the boat itself is leaking, from a seacock, a stern gland or a stuffing box, and the bilge fills slowly while you are ashore. By the time you come back the cabin floor is wet. A box on the cabin floor with the electronics inside survives. A bag on the floor does not. The simple rule is to keep valuables off the sole, in cases, in lockers that are high enough to stay dry.
What to Buy First If You Only Buy Two Things
Not everybody wants to build a complete kit. If you are packing in a hurry or on a budget, here is the order we would follow.
- A small case for the phone, the keys and the cards. It is the cheapest and most useful purchase on this list, and it protects the three things you use every day.
- A medium case for documents and medicine. This one stays in the same locker for the whole trip and is the box you would grab first.
- A larger case for camera, tablet or the emergency kit. Add it when you know what you will carry.
Whatever you choose, buy for the trip you will actually take. A family weekend on a lake does not need the same kit as a two-week charter in the Aegean, and a crew of two needs fewer boxes than a crew of eight. A few well-chosen cases, used well, beat a pile of random bags every time.
Summary: The Nine in One Glance
- Phone: sealed case with a lanyard, tested for float.
- Documents: one case per person, in the same high, dry locker.
- Keys and fobs: a micro case in the pocket.
- VHF and PLB: read the manual, register the beacon, keep it ready to use.
- Medication: a labelled case, with a printed list in English.
- Camera: a padded case, silica gel and a nightly backup.
- Power: power banks in the cabin, out of the sun, charged with care.
- Signals: follow local law on flares, and keep the rest of the kit in one bright box.
- Tablet: measured, protected and not stored on the floor.
FAQ: Waterproofing for a Sailing Trip
Does IP67 mean a case is safe at any depth?
No. IP67 means the enclosure is dust-tight and has been tested for temporary immersion, in the standard, up to 1 metre for 30 minutes. It is a very useful level of protection for splashes, rain and a drop overboard that you recover quickly, but it is not a diving rating. For anything deeper or longer, check the manufacturer's specification for that exact model.
Will a loaded case float?
It depends on the case, the contents and the weight. A small case with a phone and a few cards often floats, while a larger case full of dense equipment may sink. The only reliable answer is to test your own combination in a sink or a bath before the trip.
Can I fly with these cases?
Yes, hard cases are widely used as luggage, but airline rules on size, weight and batteries apply as usual. Lithium batteries and power banks belong in the cabin. Check your airline's cabin baggage limits before you pack, and if the case has a pressure valve, leave it in the position recommended by the manufacturer.
Do I still need a lifejacket, a tether and training if my kit is waterproof?
Absolutely. Waterproof cases protect equipment, not people. Lifejackets, tethers, a briefing for every crew member and a plan for man overboard remain the first line of safety on any boat.
How do I look after the case after the trip?
Rinse it with fresh water, dry it, check the O-ring for grit or cracks and store it with the lid slightly open. If a latch, handle or seal is damaged, it can be replaced as a spare part, which is much cheaper than replacing the case.
Most trips on the water end exactly as planned, with sunburn, good food and a pile of photos. The point of waterproofing is not to expect disaster, it is to make sure that a bad five minutes stays a bad five minutes. Pack the nine things above properly, keep them where everybody can find them, and spend the rest of the week thinking about the next anchorage. ⛵
