Lost Ship Quilt Block Pattern

New to quilting? Click here for a beginner in-depth sewing class covering all the basics.

How to Sew a Lost Ship Quilt Block

The Lost Ship quilt block is a fun and rewarding challenge that creates a striking geometric design.

Materials:

• Fabric in at least two contrasting colors
• Rotary cutter, cutting mat & quilting ruler
• Sewing machine & thread
• Iron and ironing board

Cut your fabric:

• 4 squares of Color A: 2½"
• 4 squares of Color B: 2½"
• 2 rectangles of Color A: 2½" × 4½"
• 2 rectangles of Color A: 2½" × 6½"
• 2 rectangles of Color B: 2½" × 8½"
• 1 rectangle of Color B: 2½" × 12½"

Instructions:

1. Pair one Color A square with one Color B square, right sides together. Sew a ¼" seam along one edge. Press seam to one side. Repeat to make 4 square units.
2. Sew two square units together along one edge, with the Color A squares adjacent. Press seam. Repeat to make 2 four-patch units.
3. Sew one 2½" × 4½" Color A rectangle to one side of a four-patch unit. Press seam toward the rectangle.
4. Sew one 2½" × 6½" Color A rectangle to one side of the other four-patch unit. Press seam toward the rectangle.
5. Sew the units from steps 3 and 4 together along one long edge, rectangle units adjacent. Press seam.
6. Sew one 2½" × 8½" Color B rectangle to one side of a four-patch unit. Press seam toward the rectangle. Repeat with the remaining four-patch unit and Color B rectangle.
7. Sew these two units together along one long edge. Press seam.
8. Sew the 2½" × 12½" Color B rectangle to the bottom of the unit from step 7. Press seam toward the rectangle.
9. Sew the unit from step 5 to the right side of the unit from step 8. Align edges and press seam toward the rectangle.

Congratulations — your Lost Ship quilt block is complete! Repeat to make as many blocks as needed, then arrange them in a pleasing pattern for your quilt top.

Making Half-Square Triangles

This technique eliminates the need to directly manipulate the stretchy bias of the triangle. It uses two easy-to-cut squares to produce two half-square triangles.

On the back of the lighter fabric, draw a pencil line diagonally from corner to corner.

Stack a pair of light and dark squares right sides together. Sew a ¼" seam allowance on each side of the line.

You will end up with something like this:

Now cut along the diagonal line.

Press the seam to set it, then press toward the darkest fabric.

To trim to the exact size, line up the 45° diagonal on your ruler with the seam.

Then carefully trim your block with a rotary cutter.

How to Resize Quilt Blocks

The first step in modifying any quilt block is to decide on the finished size. You can base this on doubling a pattern, cutting it in half, or working with your available fabric.

Important: Always remove the seam allowance before doubling or tripling the size. For example, if your pattern calls for 3½" squares, subtract the seam allowances (½"), double the finished block size (3" → 6"), then add the seam allowance back (½"). You'll end up cutting a 6½" piece of fabric.

Resizing Square Blocks

Add ½" to your desired finished block measurement. For a 4" finished square, cut a 4½" square of fabric.

Resizing Rectangular Blocks

Add ½" to both the length and width. To double a block that measures 3" × 4", cut a 6½" × 8½" rectangle of fabric.

Resizing Half-Square Triangle Blocks

Add ⅞" to the desired finished block size. For a 4" finished block, cut 4⅞" squares.

Resizing Quarter-Square Triangle Blocks

Add 1¼" to the desired finished block size. For a 4" finished block, cut your squares 5¼".