Beach days are supposed to be the easy part of summer. Pack the bag, load the car, find a spot, let everyone loose.
But if you're anything like me, the mental load of a beach day with kids is its own full-time job. The sunscreen that keeps washing off. The hair that takes three days to recover. The mysterious bumps that appear on everyone's thighs by Monday. The snacks that are somehow both insufficient and everywhere.
I'm a marine scientist and a mom. I built Miami Beach Bum because I kept showing up to the beach with products that weren't designed for the beach — and definitely weren't designed for what happens to your family's skin when they actually use it.
This is the guide I wish existed. Everything I actually do before, during, and after a beach day with kids — backed by marine science, tested in real ocean water, and designed to make the best part of summer easier for everyone.
Part 1: Before You Leave the House
The decisions you make before you hit the sand matter more than anything you do once you're there. Here's how to set your family up for a good skin day from the start.
The sunscreen rule that changes everything
Apply sunscreen 15 minutes before you leave — not in the parking lot, not at the beach entrance, not right before everyone runs into the water. UV filters need time to bond to the skin before they work properly. If you're applying at the water's edge, you're essentially washing it off before it's done anything.
For kids especially, apply at home with enough time for it to absorb before clothes go on. It's easier, it's less sandy, and it means you're not chasing a moving target on the beach.
What to look for on the label:
- Non-nano zinc oxide as the active ingredient
- "Water resistant (80 minutes)" — not "waterproof" (that word is FDA-banned)
- No oxybenzone or octinoxate — these are hormone disruptors detected in human bloodstream and reef tissue
- No synthetic fragrance — especially for kids' sensitive skin
The hair trick marine scientists actually use
Hair is porous. When it's dry, it absorbs whatever liquid it comes into contact with first — and in the ocean, that's saltwater. Salt then draws moisture out of the protein in your hair shaft as it dries, leaving behind the frizz, tangles, and brittle texture that can take days to recover from.
Apply Hair Shield before you go in the water. It creates a plant-based barrier — the salt interacts with the avocado oil instead of the protein in your hair. Do this for your kids before you leave the house. It takes 30 seconds and it means you won't be detangling for an hour when you get home.
Pack the bag like a scientist, not an optimist
Every mom has packed a beach bag in a hurry and arrived missing the one thing everyone needed most. Here's the list I actually use:
THE MBB BEACH BAG CHECKLIST For the mom who's done forgetting something
☀️ Mineral sunscreen (applied at home) Non-nano zinc oxide. Applied 15 min before leaving. Reapplication bottle in the bag for every 80 minutes.
🌿 Hair Shield leave-in conditioner Apply before swimming. Avocado, algae, and coconut create a salt barrier. Color safe.
🧴 Bum + Body Cream (post-swim) For the bumps that always show up after a beach day. Oregano oil + aloe. Apply after rinsing off.
🥥 Upcycled Coco Scrub (for home) Gentle exfoliation 2–3x a week keeps follicle openings clear. The pre-beach prep that prevents post-beach breakouts.
🌊 Extra towels (always more than you think) Towel drying removes sunscreen. Pat dry, don't rub, and reapply. Budget at least one towel per person plus a spare.
🎒 Change of clothes for everyone Getting out of wet swimwear within 20 minutes significantly reduces the risk of folliculitis. Pack a dry set for each kid.
Part 2: At the Beach
You made it. The bag is packed, the sunscreen is on, the kids are already running. Here's what to actually do while you're there.
The reapplication schedule nobody actually follows — but should
Most people apply sunscreen once and consider themselves covered for the day. They are not.
| When | Why | Note |
|---|---|---|
| 15 min before beach | Bonds to skin before UV exposure | Do this at home, not in the parking lot |
| After every swim or 80 min in water | Water resistance has a hard time limit | Set a timer — kids will not remind you |
| After towel drying | Towels physically remove sunscreen | Pat dry, don't rub, then reapply |
| After sweating heavily | Sweat breaks down UV filter coverage | Shade breaks are a good reapply window |
| When moving from shade to sun | UV exposure restarts the clock | Cloud cover doesn't mean no UV |
What salt water actually does to your kids' skin
Salt water is therapeutic in small doses. Magnesium in seawater reduces inflammation, and salt has mild antibacterial properties. But prolonged exposure — especially without rinsing off — has real effects worth knowing about.
The science of salt and skin:
- Salt is hygroscopic — it draws moisture from wherever it can, including your skin cells. Extended time in saltwater without rinsing dries out the skin barrier.
- Salt water disrupts the skin's acid mantle — the pH-balanced protective layer that keeps bacteria in check. A disrupted acid mantle means skin is more vulnerable to the bacteria that cause folliculitis.
- In kids especially, the skin barrier is thinner and more permeable than adult skin. They absorb more, lose more moisture, and react faster to environmental exposure.
The hat rule for kids under 5
UV radiation affects children's skin and eyes disproportionately because their skin is thinner and their pupils are larger, letting in more UV light. A wide-brim hat that covers the face, ears, and neck isn't optional for young kids — it's genuinely the single most effective sun protection tool you have, even more effective than sunscreen on exposed areas.
The one thing I tell every parent: Sunscreen is not a substitute for shade and timing. The UV index in most of the US peaks between 10am and 2pm. If you're at the beach with young kids, the safest two hours are before 10am and after 3pm. Everything else is managing risk, not eliminating it.
Part 3: The Post-Beach Routine (The Part Everyone Skips)
What you do in the 30 minutes after you leave the beach matters more than most people realise. This is where the skin damage from the day either gets managed or compounds into the bumps, frizz, and dry skin that last the rest of the week.
Step 1: Rinse within 20 minutes
Salt, chlorine, sunscreen residue, and the bacteria from beach and pool water all sit on the skin and continue to interact with it until you rinse them off. The longer they sit, the more they disrupt the skin's pH and the acid mantle. A beach shower at the exit is fine. A real shower at home is better. The point is not to let it sit.
Step 2: Pat dry — don't rub
Rubbing with a towel creates friction on already sun-exposed, salt-stressed skin and removes the moisture you want to lock in. Pat dry instead, and moisturise while the skin is still slightly damp — damp skin absorbs product up to 40% more effectively than dry skin.
Step 3: Apply Bum + Body Cream while skin is still damp
This is the step that prevents the bumps. Folliculitis — the small red bumps most active people get on their thighs, bum, and back after a beach or pool day — is caused by bacteria colonising hair follicles in the warm, moist, friction-exposed environment of a day in the water and wet swimwear.
Oregano oil, the hero ingredient in Bum + Body Cream, has demonstrated antimicrobial activity against the specific bacteria causing folliculitis in peer-reviewed research. Applied post-swim while skin is still damp, it works with the skin rather than stripping it.
Step 4: Deal with the hair
Apply a small amount of Hair Shield through damp lengths and either let air dry or use low heat. For kids who won't sit still for detangling: Hair Shield significantly reduces the knot situation because the plant-based barrier keeps the cuticle smoother throughout the day. Start with it before the swim and the after-beach detangle becomes manageable.
Step 5: Change out of wet swimwear immediately
Wet swimwear is warm, tight, and bacteria-friendly. The longer your kids stay in a wet swimsuit, the more time bacteria have to work their way into hair follicles. Get everyone into dry clothes within 20 minutes of leaving the beach.
Part 4: The Science-Backed Guide by Age
Every kid's skin is different, and needs change as they grow. Here's how I think about sun and skin protection at different ages.
Babies & Toddlers (Under 3 years)
- Shade is the primary protection — UV tent or umbrella essential
- Mineral sunscreen only — no chemical filters
- UPF 50+ swimwear on trunk and shoulders
- Wide-brim hat non-negotiable
- Limit direct sun exposure between 10am–2pm
Little Kids (3 to 8 years)
- Mineral SPF 30+ minimum, applied at home before leaving
- Reapply every 80 minutes — set a phone timer
- Hair Shield before swimming
- Change out of wet swimwear within 20 min
- Bum + Body Cream post-swim for folliculitis prevention
Tweens & Teens (9 years and up)
- SPF 50 mineral sunscreen — face and body
- Introduce them to reading sunscreen labels now
- Hair Shield — especially for colored or highlighted hair
- Bum + Body Cream for post-swim folliculitis — particularly relevant for teens in activewear
- Upcycled Coco Scrub 2–3x per week to keep follicles clear
Part 5: The Questions I Get Asked Most
Every time I post about beach skin science, the same questions come up. Here are the ones I hear most from moms — answered honestly.
"Is the spray sunscreen I bought actually working?"
Probably not as well as you think. Spray sunscreens are notoriously difficult to apply at adequate coverage — most people use about 25% of the amount needed for the SPF on the label to actually be accurate. If you're using a spray on kids, spray until the skin looks wet, then rub it in. And avoid spraying near faces — use a gentle mineral lotion for face application instead.
"My kid refuses to wear sunscreen. What do I do?"
Switch formulas. Most sunscreen resistance in kids comes from texture and smell — the white cast, the greasy feel, the chemical scent. A lightweight mineral formula without synthetic fragrance is a genuinely different experience. Our Save Face mineral serum has zero white cast and no fragrance, and it's what I use on my daughter's face.
"Do I really need to reapply every 80 minutes? We barely stay in the water that long."
The 80-minute clock starts from when you get in the water, not from when you applied. But water resistance degrades faster in salt water than fresh water because salt physically disrupts the formula. If you're at the ocean, reapply every 60 minutes to be safe. And the clock resets to zero every time you towel dry.
"Is SPF in makeup enough for a beach day?"
No. SPF in makeup is applied in much smaller quantities than sunscreen — you'd need to apply about 7 times the normal amount of foundation to achieve the SPF on the label. Makeup SPF is a supplement for incidental daily exposure, not protection for extended sun time. Apply mineral sunscreen first, let it set, then apply makeup on top.
Part 6: The Ingredients That Don't Belong Near Your Family
As a marine scientist and a mom, I think about ingredients differently than most people. Here are the ones I removed from our home completely — and why.
| Ingredient | Why It's a Problem | Where It Hides |
|---|---|---|
| Oxybenzone | Detected in human bloodstream after one application. Hormone disruptor. Linked to coral bleaching at low concentrations. | Most chemical sunscreens, especially sprays |
| Octinoxate | Detected in fish tissue in US coastal waters. Endocrine disrupting effects in aquatic organisms. | Chemical SPF lotions, lip balms with SPF |
| Polyethylene | Plastic microbeads. Non-biodegradable, accumulate in marine organisms, detected in fish tissue. | Body scrubs, some face washes |
| Synthetic fragrance | Catch-all term hiding dozens of undisclosed chemicals. Linked to skin sensitisation and microbiome disruption. | Body washes, lotions, sunscreens |
| Petroleum derivatives | Occlusive agents that block follicle openings. Associated with hormonal disruption at high exposure. | Many body creams, baby oils, conventional moisturisers |
The Beach Day Checklist: Quick Reference
BEFORE YOU LEAVE: ✔ Apply mineral sunscreen 15 min before leaving ✔ Apply Hair Shield ✔ Pack change of clothes
AT THE BEACH: ✔ Reapply every 80 min ✔ Reapply after towel drying ✔ Shade between 10am–2pm ✔ Wide-brim hats on young kids
AFTER THE BEACH: ✔ Rinse within 20 min ✔ Pat dry, don't rub ✔ Apply Bum + Body Cream while damp ✔ Apply Hair Shield through damp lengths ✔ Change out of wet swimwear
What We Made for Beach Days
Every product at Miami Beach Bum was built around what I actually needed as a marine scientist and a mom who spends real time in real water.
Hair Shield — Avocado + algae + coconut leave-in conditioner. Pre-swim barrier, post-swim repair. Color safe. $19
Bum + Body Cream — Oregano + aloe + jojoba. For folliculitis, body acne, razor burn, post-swim irritation. $24–$38
Blocked Sunscreen — SPF 50, non-nano zinc oxide, 80 min water resistant. Non-aerosol BOV spray. Fragrance free. $24
Available at Whole Foods, Revolve, Nordstrom, and 400+ stores nationwide. Link in bio for the full range.
The Bottom Line
Beach days are supposed to be the easy part. The science behind protecting your family's skin doesn't have to be complicated — it just has to be right.
Apply before you leave. Reapply on a timer. Rinse within 20 minutes. Change out of wet clothes. Use products that were actually designed for what your skin faces in the water.
The rest is sand, sunsets, and the kind of summer memories your kids will talk about for years.