MARKSIGN Truck Bed Bag (100% Waterproof) with Built-in Ratchet Tie-Down Straps, 26 Cubic Feet

If you haul anything that doesn’t like getting wet, MARKSIGN’s truck bed bag is the kind of accessory you’ll appreciate more the more you use it. It’s built around one job: keeping cargo protected from rain and road grime while you still have a practical way to secure and access it.

The essentials

The MARKSIGN Truck Bed Bag is a waterproof cargo bag designed to sit in your truck bed. The bag size is listed as 51'' x 40'' x 22'', with a capacity of 26 cubic feet—so it’s meant for medium to larger truck beds where you want one covered space for gear rather than loose items flying around.

On paper, it’s designed for people who regularly move “real life” cargo: sports equipment, camping supplies, tools, or family essentials. The brand also notes fit for a range of truck sizes, but the bag’s listed dimensions are what ultimately decide whether it works for your setup.

What makes it work in messy weather

This bag’s weather protection is the headline feature. The entire bag is sealed with 500D tarp fabric “with no needle holes,” and it uses a waterproof, vinyl-coated zipper to keep moisture out. There’s also an extra rain curtain sealed with Velcro that helps cover the zipper area when conditions are bad.

That combination matters, because zippers are often where cargo bags fail over time. A bonus detail here is the rain flap approach—when storms roll in, you’re not just relying on one barrier.

Security and handling (not just storage)

Cargo protection is great, but a bag that’s hard to load and tie down becomes annoying fast. This one includes 4 built-in ratchet tie-down straps, intended to connect to your truck’s cargo tie-down anchors. When the straps aren’t in use, you can store them neatly in Velcro panels at each corner.

The bag also has 4 side handles—two on each side—which makes it easier to pull the bag out and position it in the bed. That’s a small thing until you’re doing this in a parking lot, one-handed, with wind blowing and time running.

Capacity: what it’s likely good for, and what to watch

The listing frames it as a way to carry everything a family of 5 to 6 people might need, and the 26 cubic feet capacity supports that idea. In practical terms, it’s the sort of bag that can replace multiple smaller covers when you want one contained “dump zone” for bulky items.

Still, take note: if your goal is to move taller, oddly shaped items or if your truck bed layout is tight, you’ll want to double-check the listed dimensions (51'' x 40'' x 22'') against your bed space and tie-down anchor placement. A waterproof bag can be the right idea and still be frustrating if it doesn’t physically fit your cargo and your truck.

Included extras and day-to-day convenience

Besides the main waterproof cargo bag, the package includes an additional drawstring storage bag for easier storage when the cargo bag isn’t in use. If you keep accessories in the garage or trunk, this is the kind of “boring but useful” detail that prevents clutter.

Mini FAQ

Is this bag fully waterproof, or just water-resistant?

The listing specifically describes it as 100% waterproof, using 500D tarp fabric with no needle holes plus a vinyl-coated waterproof zipper and a Velcro-sealed rain curtain over the zipper area.

How do you secure it in the truck bed?

It comes with 4 built-in ratchet tie-down straps meant to attach to your truck’s cargo tie-down anchors.

Does it work for any truck size?

The brand states it fits any truck size, but the most reliable way to judge fit is the stated bag dimensions (51'' x 40'' x 22'') and how that matches your truck bed.

Is it easy to store when not in use?

Yes—there’s also a separate drawstring storage bag included.

Should you buy it?

It makes sense if you want one large, sealed cargo bag for wet-weather protection, and you also want built-in ratchet straps and handles so loading and tying down isn’t a chore.

You may want to skip it if your truck bed space doesn’t match the listed size, or if you prefer a setup that’s more modular than one big container. In that case, the dimensions and the single-bag approach could feel restrictive—even if the waterproofing is strong.

As a general rule, this is a solid buy for anyone who regularly hauls gear that needs cover (rainy commutes, camping weekends, road trips). Just verify fit against your bed and anchors before committing, because that’s where “works in practice” starts and where assumptions can fall short.