Attire: Bright & Breezy Resort-Wear
Bright, breezy, elegant, comfortable resort-wear. You should dress like you'll be holding an Aperol spritz on an Italian terrace at golden hour (...in St. Augustine, FL).
Examples:

Neutral Linens & Tans (White linen button-downs for men are okay!)
Bright Pinks & Corals
Jewel-tone Blues & Turquoise
Soft Yellow & Green Pastels & Florals
Women: Semi-formal resort-wear is encouraged! Colorful cocktail-, midi-, or maxi-length dresses with ruffles, cheerful prints, fun cut-outs, and satiny, flowy fabrics.
Men: Linen fabrics and light-weight short sleeve collared shirts and button downs are encouraged! Light colored solid shirts or minimalist prints. White shirts are okay. For colors - khaki/tan, shades of blue, green, coral, pastels. Long or short-sleeve collared shirts are great - jackets are totally optional. Khaki or tan pants are ideal, and please avoid black slacks/black jackets, but blue is great! Please, no shorts.
Shoes: For women, please wear shoes that are comfortable enough to walk the wooden boardwalk over to the beach ceremony! Strappy sandals or low heels encouraged! For men, please feel free to go casual with your footwear! Sperry boat shoes, loafers, clean converse, nice lifestyle sneakers, even nice sandals. Dress shoes not required, socks not required!