How to Prevent Seasickness on a Dive Boat: What Actually Works

You’ve planned the trip, packed the gear, and been counting down for weeks. Then the boat ride hits and your dream dive day turns into a long stare at the horizon.

Seasickness is one of the most common ways a great dive day goes sideways. The good news is that it’s very manageable. Here’s how to prevent seasickness on a dive boat, plus what to do if it shows up anyway.

Why Seasickness Happens

Your eyes see a stable boat while your inner ear feels it moving up and down. Your brain gets conflicting signals, and the result is nausea, dizziness, and vomiting.

It’s more than an annoyance. Vomiting can lead to dehydration, and feeling miserable can lead to rushed safety checks, skipped hydration, and missed changes in conditions. Prevention is part of dive safety.

How to Prevent Seasickness Before You Board

Pick the Right Boat

• Go big. Larger boats move less. Catamarans are a great option if available.

• Choose closer sites when you can, so the ride is shorter.

Plan the Night Before

• Skip the alcohol and heavy meals.

• Hydrate!! Dehydration makes symptoms worse.

• Consider medication early. Some divers find taking an antiemetic the night before works better than the morning of.

The Morning Of

• Eat light. Think toast or a banana, not a greasy breakfast.

• Gear up at the dock. Looking down to assemble gear while the boat moves is a classic trigger.

Medication: What Divers Use

Talk to your doctor before trying anything. Here’s the landscape:

Over-the-counter: Bonine and Dramamine Less Drowsy (meclizine), Dramamine (dimenhydrinate), Marezine (cyclizine), and Benadryl (diphenhydramine). Drowsiness is a common side effect of this group, which matters when you’re diving. Meclizine is often a first choice for divers.

Prescription: The scopolamine patch. It affects the central nervous system, so side effects (dry mouth and blurred vision are the most common) can affect diving. If you feel dizzy, nauseated, or start vomiting within 24 hours of a dive while wearing it, contact a physician.

The golden rule: never take a medication for the first time on a dive day. Test it at home on a day when you don’t need to drive or operate anything, and see how you feel.

Natural Options

Ginger (tea, candy, ginger ale) and acupressure wristbands are popular. The evidence is mixed, but they’re generally low-risk and worth a try, especially alongside other strategies. As with medication, test them before the trip.

On the Boat

• Get fresh air. Stay out of stuffy cabins and below-deck areas.

• Watch the horizon. It gives your brain a fixed reference point.

• Sit midship and low. That’s where there’s less motion.

• Don’t overheat. Sitting in direct sun can make nausea worse.

• Keep sipping water.

If Seasickness Hits Anyway

• Tell the crew early. Medication won’t kick in fast once symptoms start.

• Know your options. Many divers feel better once they’re in the water, and DAN suggests entering early if you start to feel unwell. But skip the dive if symptoms are severe.

• Rehydrate. Vomiting dehydrates you quickly.

• Ask your instructor or divemaster how to handle vomiting through a regulator before you need it.

Gear Up for Boat Days

Let’s be honest: no piece of gear cures seasickness. But the right setup makes the whole boat day easier.

A Plunge UPF 50+ Dive Suit gives you full sun coverage for the ride out, the surface intervals, and the ride home. That lets you sit in the fresh air at the back of the boat without burning, and without sunscreen to reapply.

When you’re back on deck, our hooded microfiber towel is your grab-and-go layer. It dries quickly, the full hood gives you privacy to change out of wet gear, and the front pocket keeps your essentials handy. And if you’re layering a wetsuit, the suit under it makes getting in and out much easier, which helps when you’re already feeling off.

What the Fish?!

The Ocean Sunfish: A Giant That Looks Like It’s Missing Its Back Half

Picture a fish that’s basically a giant, flat, silver head with fins. That’s the ocean sunfish, or mola. Sunfish are the heaviest bony fish in the world, with the biggest reaching nearly 5,000 pounds. Their back end looks chopped off because their tail fin doesn’t grow along with the rest of the body after they hatch.

They get their name from sunbathing, floating on their sides at the surface, apparently very comfortable with the waves. Basking also helps them get cleaned: seabirds peck parasites off their skin, and they visit reef cleaning stations where smaller fish do the same. Sunfish can carry dozens of parasite species, so they need the help.

For years, jellyfish were assumed to be their main food. More recent genetic work suggests they’re generalist predators, eating mostly small fish, fish larvae, squid, and crustaceans, with jellyfish and salps making up a smaller share.

Divers who want to see one head to cleaning stations like those around Bali, where local operators say the best sightings run roughly July through October.

Stay Salty

Prevention is the whole game: pick a good boat, plan ahead, test your remedies at home, and get fresh air. Sort out the boat ride, and the reef takes care of the rest.