Traditional / Public Domain — dates to the late 1800s, origin in coastal New England quilting communities
An extraordinary optical illusion: flat piecing that creates the appearance of rolling ocean waves. The block combines square-in-a-square units, flying geese, and plain squares to create curved-looking lines from entirely straight seams. One of the most visually stunning traditional patterns.
Storm at Sea emerged from the coastal New England quilting tradition in the late 1800s. The pattern mimics the rolling, turbulent surface of the ocean during a storm — remarkable because the entire illusion is created from straight seams. No curves are pieced, yet the finished quilt appears to undulate like water.
In seafaring communities, quilters who had witnessed ocean storms captured that power in fabric. The pattern was especially popular in Massachusetts, Maine, and the mid-Atlantic coastal states. It remains one of the most admired traditional patterns for its combination of mathematical precision and visual drama. Quilters from the Nantucket and Cape Cod traditions were particularly known for this pattern.
Also known as: Rolling Sea, Ocean Waves (sometimes confused), Mariner's Fancy
finished Block Size
12" (composed of 4 sub-blocks)
seam Allowance
1/4"
grid Basis
4x4 grid of sub-units: square-in-a-square + flying geese + small squares
units Required
1 large center SiaS + 4 small SiaS + 4 flying geese + 4 corner squares
All measurements include 1/4" seam allowance unless noted.
| Piece | Fabric | Cut Size | Qty | Notes |
|---|---|---|---|---|
| Large Center Square | Dark | 3 1/2" x 3 1/2" | 1 | Center of large SiaS |
| Large SiaS Triangle | Light | 3" x 3" | 2 | Cut once diagonally — 4 triangles for large SiaS |
| Small Center Square | Medium | 2 1/2" x 2 1/2" | 4 | Centers of 4 small SiaS units |
| Small SiaS Triangle | Dark | 2 1/4" x 2 1/4" | 4 | Cut once diag — 8 triangles for small SiaS |
| Goose Rectangle | Light | 2 1/2" x 4 1/2" | 4 | Flying geese bodies |
| Goose Corner Square | Medium | 2 1/2" x 2 1/2" | 8 | For stitch-and-flip goose construction |
| Corner Square | Dark | 2 1/2" x 2 1/2" | 4 | Four outer corners of the block |
Take the 3 1/2" dark center square. Cut two 3" light squares in half diagonally (4 triangles). Sew two opposite triangles to the center, press. Sew the remaining two, press. Trim to 4 1/2" square. This is your block center.
Tip: Handle bias edges gently — spray starch before cutting for stability.
Take four 2 1/2" medium center squares. Cut four 2 1/4" dark squares diagonally (8 triangles). Add triangles to opposite sides first, then remaining sides. Trim each to 2 1/2" square.
Use the stitch-and-flip method: Draw diagonals on eight 2 1/2" medium squares. Place one on the right half of a 2 1/2" x 4 1/2" light rectangle. Sew, trim, press. Repeat on left. Make 4 geese.
Layout in a 3x3 grid: Row 1 = Small SiaS, Goose (pointing up), Small SiaS. Row 2 = Goose (pointing right), Large center SiaS, Goose (pointing left). Row 3 = Small SiaS, Goose (pointing down), Small SiaS. This arrangement creates the wave illusion.
Tip: The wave illusion depends on correct orientation of EVERY unit. Double-check before sewing.
Sew each row with precise 1/4" seams. Press Row 1 and 3 seams toward the small SiaS units. Press Row 2 seams toward the center.
Nest seams and sew all three rows together. Press.
Block should measure 12 1/2" square. Step back and view from a distance — you should see the wave/curve illusion clearly. If a unit is turned wrong, the wave breaks.
See how this traditional pattern looks in different color combinations.
Side by side — creates rolling waves across the quilt
All blocks same orientation — waves flow in one direction
Rotating blocks — creates a turbulent, choppy sea effect