Use larger hook sizes to make larger size.

Reading this pattern:
(1sc) x2 means 1 single crochet in a station and 1 single crochet in the next station. The ( ) signify what repeats and x2 means repeat twice. Also BL means back loop and ch means chain. Crocheting in the back loop is what gives the ridges to the seashell.

If you have any questions about the pattern, please email me. This the first pattern I ever published and I am going to improve it with photos and diagrams once I get some time to do so. Plus I will email the new version (once complete) to my previous customers. Thank you!