Giant Waterproof Backpack


It is obscenely huge. It fastens shut and watertight with a roll-top closure. A backpack harness system lets you strap it on and hike, ferrying immense loads through airports and down backwoods portage trails alike.

The SealLine Pro Packs are essentially giant vinyl duffel bags. They open wide to reveal a capacious hold that can swallow about 7,000 cubic inches worth of gear.

SealLine-ProPacks photo.jpg

SealLine Pro Packs

I have used a SealLine Pro Pack on a half-dozen trips this year, including for international travel as well as on a raft excursion where the pack was tied to the deck. At $169.95, the handy and bombproof bag — mine’s been dubbed “Big Yellow” — has proven its worth a few times over.

The Pro Pack is 100 percent waterproof for terrestrial use. Rain, sleet, snow, or dripping cargo holds are no match for the thick vinyl fabric and roll-down top.

If you plan to use it whitewater rafting, Pro Pack manufacturer Cascade Designs ( says it will withstand quick submersions and will float if dropped in the water.

The pack has a reinforced vinyl bathtub-style bottom and tough vinyl sides. Webbing straps cinch to tighten down the top. Durable buckles snap it shut.

The pack’s adjustable suspension system is supportive for big loads. There’s a padded hip belt and a grab handle to lift the sack off the ground. For snag-free transport, the backpack harness and belts can be removed.

I loaded the Pro Pack with 50 pounds or more on numerous occasions. The pack straps and belt are adequate for huge loads, though the rigid panel under your back can bow out from the pack body with extreme weight.

The pack comes in four colors and weighs about six pounds when empty. It stands about 30 inches tall. As a bonus, the pack is made in the USA in a Seattle factory.

Overall, “Big Yellow” has been a solid product after much abuse this year. It totes huge loads. It keeps my gear dry. It does exactly what it was designed to do.

—Stephen Regenold is founder and editor of

Posted by Greg Seitz - 07/30/2010 10:01 AM

We generally use one big Sealine pack for Boundary Waters canoe trips. They’re great for packing sleeping bags and other stuff in that it feels really good knowing will be dry no matter what when we set up camp in the evening. They are a hassle to get into and out of during the day, for say a water bottle or other types of regularly used gear… a Duluth Pack is nice for being able to easily shove stuff under the flap of when arriving at a portage. But I sure do like that peace-of-mind of a dry sleeping bag at the end of the day.

Posted by Maurice TAY - 02/18/2011 08:39 PM

Dear Sir,

Can a computer metal casing measuring 29” x 27” x 12.5” fit inside this Giant Waterproof Backpack ? Thanks


Posted by AV - 04/14/2013 01:33 AM


I am planning a 2-week hiking trip that will involve a lot of scrambling and want to buy this bag. Would you recommend it for this purpose? Sales staff in outdoor gear shops tell me that it will be a nightmare to carry this over long distances. What do you think? Is hipbelt good enough for long trips?

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