Building sand castles is one sure way to get into the spirit of summer, and the city of Edmonds Parks and Recreation department on Thursday will help beach enthusiasts do just that.

From 10 a.m. to 12:30 p.m., sculptors of all ages can display their skills at Marina Beach. The free event is open to everyone — families, groups of friends, youth and summer camp groups and others, recreation coordinator Tammy Rankins said.

“Sign-up is at 10 a.m., and participants can form teams or build on their own,” she said. “You must bring your own building tools. Once you sign up, you are given a numbered, colored flag that will identify which category you are in.”

This year’s categories are Sandcastles with Drawbridge and Moat and Your Favorite Creature (real, mythical, wild or domestic).

While dimensions and number of features are not restricted, other rules apply:

Sculptors may not disturb marine life or vegetation.

They must stay out of eelgrass beds, building only in sandy areas.

When bringing up water, they must not scoop up mud.

Contestants will be entered into three age groups: 13 and under (with adults providing only verbal guidance), family, and kids 14 and up.

Unique winners from 2006 were a dino-crab and a “mermaid named Sandy listening to an iPod,” Rankins said.

“Judges will walk around the beach beginning at noon,” she said, “to see all the sculptures and visit with the participants, and then at 12:30 p.m., we announce the (six) Golden Bucket winners … Golden Buckets, which are plaques filled with saltwater taffy, are awarded to the winners of each category.”

Nama’s Candy Store, the event sponsor, will provide those fitting rewards.

People should attend, Rankins said, simply because “it’s a fun day at the beach!

“Families can pack lunches, build their castles and sculptures, meet new people and enjoy the view of the Puget Sound. The contest date is chosen based on the tide being at its farthest point out during the contest, so participants do not have to rush to create.”

While kids can use their imaginations to build and design anything in the sand, as Rankins described it, the day isn’t intended just as child’s play.

Adults have said playing in the sand was therapeutic for them, she said. “Many families return each year excited for the contest. Local day camps and day cares are regular participants as well.”

Some groups come prepared with household sand sculpting tools such as empty plastic containers, brooms, spoons, buckets, shovels and decorative pieces.

“One of the best parts is the excitement groups and kids get when they are explaining their creation to the judges,” Rankins said. “The judges walk around with clipboards, so when participants spot them, they are eager to show off their creations. Each year, there are always two or three pretty amazing sculptures that are well beyond our amateur contest.”