The night my gear got soaked while camping by the river. My conclusion after researching Sea to Summit and ORTLIEB waterproof bags

Pitching my tarp by the river was the worst decision I could have made.

I never expected a sudden evening shower.

A riverside campsite. The water was close and the view was amazing, so I set up my tarp there. It had been sunny until the evening, so I kept my rain gear in my bag.

6:00 PM. The sky suddenly turned dark, and ten minutes later, it started raining cats and dogs.

Even though I had a tarp, all my gear got soaked. That's because I hadn't put a cover on my backpack. My change of clothes, wallet, and portable battery were all drenched. I escaped into my tent, but by then, it was already too late.

“I should have bought a waterproof bag,” I thought while wringing out my jacket. Since that night, I’ve been obsessively researching waterproof bags.

How to correctly interpret the “waterproof rating” of waterproof bags

First, there is something you need to know. There aretwo main types of waterproof bag construction: “welded seam + roll-top” and “zippered.”

Roll-top constructionis a method where you fold the opening of the bag multiple times and secure it with a clip. Because water cannot enter through the opening, it can achieve near-total waterproof performance. This is the structure used in almost all mountaineering, kayaking, and river activities.

IPX ratingsare also worth checking. IPX6 means it can “withstand powerful water jets,” IPX7 means it can “withstand immersion for 30 minutes,” and IPX8 supports “continuous underwater use.” For camping rain or river play, IPX6 to 7 is sufficient.

One thing to be careful about is that most “waterproof bags” sold at 100-yen shops are zippered, and manycannot withstand heavy rain or submersion. It is important to check the construction on the spec sheet.

Sea to Summit Ultra-Sil Dry Sack | The go-to choice if lightness is your top priority

The Ultra-Sil Dry Sack from the Australian outdoor brand “Sea to Summit” features an astonishingly lightweight of just 36g (8L).

The material is ultra-thin silicone-coated nylon. When folded, it becomes palm-sized. It is a staple item for backpackers and UL (ultra-light) oriented solo campers, and many people use it as a stuff sack for tents or as an inner bag for sleeping bags.

However, there is a point to note. Because thematerial is thin, there is a risk of it puncturingif it comes into contact with sharp objects or rocks. It is not suitable for use on rocky riverbanks or for storing heavy gear directly. The correct way to use it is as a “dedicated cover for light clothing and sleeping bags.”

The opening is a roll-top style, which you fold at least three times and secure with a buckle. In reviews from people who have actually used it, many say, “Even after being in heavy rain for an hour, the contents were completely dry,” so the waterproof performance is at a reliable level.

The price is 2,000 to 3,500 yen (depending on capacity). It is a product that serves asthe first choice for those who want to cut weight but still need waterproofing.

ORTLIEB Dry Bag PS10 | If you choose based on durability, it has 30 years of proven performance

The German waterproof bag brand “ORTLIEB” has a track record of over 30 years in the kayaking and bicycle touring world. TheDry Bag PS10is a flagship product that is also easy to use for solo camping.

The material is 210D nylon. It is thicker than the Ultra-Sil and is resistant to damage even when rubbed against rocks or the ground. Because it hasno seams due to welded construction, there is zero water ingress through seams. It uses a structure where you roll the top three times and secure it with a buckle, ensuring IPX6-equivalent waterproof performance.

The 7L model weighs about 88g. It is heavier than the Ultra-Sil, but its durability is on a different level. Sizes range from 1.5L to 60L, allowing you to choose according to your needs.

The price for a 7L bag is around 3,500 to 4,500 yen. It is by no means cheap, but many reviews prove that it lasts for over 5 years if you buy one It is not a bad choice in terms of cost-performance.

It is suitable for those who think, 'I want to protect my gear all together. I don't mind if it's a bit heavy.' If you want to protect your fire gloves, change of clothes, and food in one bag, choosing this is the right answer.

The best way to use waterproof bags is to 'have multiple bags for different purposes'

I learned something after researching. It is the fact that even if you buy only one type of waterproof bag, its role will be biased.

The ideal way to use them is as follows:

Lightweight clothing such as changes of clothes and sleeping bags → Sea to Summit Ultra-Sil (prioritizing lightness)

Important items such as wallets, mobile batteries, and chargers → ORTLIEB Dry Bag PS10 (prioritizing durability)

If you pack your backpack by separating items into a 'clothing bag (Ultra-Sil)' and an 'electronic device bag (PS10)', you can create a state where the contents remain unharmed even if the backpack itself gets wet. A backpack cover is just an auxiliary item and does not provide complete waterproofing. I believe this combination is the correct answer for waterproofing measures.

Who it is for, and who it is not for

Who Sea to Summit Ultra-Sil is for

• Those who are UL-oriented and want to shave off weight by the gram
• Those who want to use it as a sub-bag for day camping or day hiking
• Those who want to use it as a moisture-proof bag for sleeping bags and clothing

Who ORTLIEB Dry Bag PS10 is for

• Those who often go to waterside areas such as riversides and lakesides
• Those who have a lot of luggage for consecutive overnight stays or want to reliably protect important gear
• Those who want to use one bag for over 5 years

Who neither is for

• Canyoning or kayaking where complete submersion is expected → Requires a double-rolled roll-top plus a dedicated waterproof case

As far as my research goes, if you're going to buy just one to start, the ORTLIEB PS10 7L is my initial answer. The price is on the higher side, but it can be used by rivers or in the mountains and is resistant to external damage. It's realistic to start by using 100-yen shop waterproof pouches for your change of clothes while using this to protect only your essential items.

Summary: Dry bags are not insurance, they are a necessity

Bringing a dry bag camping is not "insurance." When camping by rivers, lakes, or during the rainy season, not having a dry bag is "being unprepared."

While you're thinking, "I'll just buy one for the next trip," your power bank will die. Your wallet will get soaked. You'll run out of dry clothes. That's what happened to me.

The conclusion on how to choose can be summed up in one sentence. If weight is your priority, go with Sea to Summit; if durability and peace of mind are your priorities, go with ORTLIEB. There's no need to be torn between these two options.

Have you ever had your gear get wet while camping? In what kind of situation did you regret it? Let me know in the comments. I want to find the "correct answer" for waterproofing together.