Loosely ch 93.
Foundation: Row 1 Hdc in 3rd ch from hook and each ch to end, ch 5, turn.
Row 2 (Ch 5 counts as first tr and ch-1 space.) Tr in first hdc, skip 5 hdc, * in next hdc work [tr, ch 1] 4 times, tr in same hdc (shell consisting of 5 tr and 4 ch-1 spaces), skip 5 hdc, repeat from *, end in last hdc work (tr, ch 1) twice, tr in turning ch, ch 2, turn.
Row 3 Skip first tr, hdc in each tr and ch-1 space across, end 1 hdc in each of the top 2 chs of ch-5 (turning ch), ch 5, turn.
Row 4 Tr in first hdc, skip 6 hdc, shell in next hdc, * skip 8 hdc, shell in next hdc, repeat from *, end skip 7 hdc, (tr, ch 1) twice in last hdc, tr in turning ch, ch 2, turn. Repeat Rows 3 and 4 for pattern.
Work to approximately 32 inches from beginning, ending with an hdc row. Fasten off.
Work 1 row sc along each side edge of cover, beginning and ending at corners.