← Gear database

Marmot Plasma 15°F vs Sea to Summit Spark 30 Sleeping Bag

Weight and specs compared for 2026 — and which one to choose.

Sea to Summit Spark 30 Sleeping Bag is the lighter option — 368 g lighter than the Marmot Plasma 15°F (43% less weight). If grams matter to you, that is the one to beat.
shopping_cart Check today's price on Amazon
Spec Marmot Plasma 15°F Sea to Summit Spark 30 Sleeping Bag
Weight 850 g · 0.850 kg · 1.87 lb 482 g · 0.482 kg · 1.06 lb
Brand Marmot Sea to Summit
Category Sleep System Sleep System
Marmot Plasma 15°F
850 g

800-fill down sleeping bag rated to 15°F (-9°C).

Full details →
Sea to Summit Spark 30 Sleeping Bag
482 g

Ultralight 30°F mummy bag filled with 850+ loft down. Differential cut and ripstop shell deliver excellent warmth-to-weight ratio.

Full details →

HikeLoad is reader-supported. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Learn more.

Marmot Plasma 15°F vs Sea to Summit Spark 30 Sleeping Bag: which should you buy?

If saving weight is your priority, the Sea to Summit Spark 30 Sleeping Bag wins — at 482 g it is 368 g (43%) lighter than the Marmot Plasma 15°F (850 g). That said, the heavier option may justify the extra grams with more capacity, durability or comfort, so weigh the trade-off against how you'll use it.

See where both rank against everything else in this category on the lightest sleep system page, or browse the full gear weight database.

More sleep system comparisons

Marmot Plasma 15°F vs Sea to Summit Aeros Ultralight Pillow Marmot Plasma 15°F vs Sea to Summit Aeros Ultralight Pillow (Regular) Marmot Plasma 15°F vs NEMO Fillo Elite Marmot Plasma 15°F vs Nemo Fillo Elite Wide UL Marmot Plasma 15°F vs Nemo Equipment Tensor Elite Ultralight Marmot Plasma 15°F vs NEMO Equipment Tensor Elite Sleeping Pad