Seasickness on the Plymouth to Roscoff Ferry: What to Expect and How to Prepare

Worried about seasickness before your Plymouth to Roscoff crossing? You’re not alone — it’s one of the most common questions from first-time travellers on this route. The good news: most crossings are calm, and there’s a lot you can do before and during your journey to minimise the risk. This guide covers when to travel if you’re prone to motion sickness, where to sit or stay onboard, and practical steps to feel your best. Wondering how rough the crossing generally is? See our guide: Is Plymouth to Roscoff a Rough Crossing?

Last updated: July 2026 | General travel guidance only — always speak to a pharmacist or doctor for medical advice specific to you or your family.

How Rough Is the Plymouth to Roscoff Crossing, Really?

The Plymouth to Roscoff route crosses open water across the western English Channel, which makes it a longer and more exposed crossing than short hops like Dover–Calais. That said, “open water” doesn’t mean “rough water” — most sailings are perfectly comfortable, especially in spring and summer. Large ferries like the Armorique and Pont-Aven are large, stable vessels built for Channel crossings, and their size alone means gentle swells are barely noticeable most of the time. Genuinely rough conditions are the exception rather than the rule, and Brittany Ferries will delay or reschedule sailings in advance of forecast severe weather rather than sail into it.

Day Crossing vs Overnight Crossing: Which Is Easier on Seasickness?

There’s no single right answer here — it depends on how your body responds. A daytime crossing lets you stay on deck, watch the horizon, and move around freely, which helps many people avoid symptoms altogether. An overnight crossing means you can go straight to your cabin and sleep through most of the journey — if you’re asleep, you’re generally not aware of motion. Lying down itself tends to help too: it reduces the amount of conflicting movement your eyes and inner ear are processing compared with standing or sitting upright. The trade-off is that lying down in a windowless inside cabin can worsen symptoms for some people if they do wake up feeling off. If you know you’re sensitive to motion, consider booking an outside cabin with a window for a visual horizon reference — see our cabins guide for the full range of options on both ships.

Practical Tips to Prevent Seasickness

A little preparation before you board goes a long way.

Travelling With Kids or Pets Who Get Seasick

Children can be more prone to motion sickness than adults, so the same principles apply — fresh air, a horizon view, light snacks rather than a heavy meal, and avoiding screens. Bring a favourite blanket or toy to help them settle if they head to the cabin to rest. Speak to a pharmacist in advance about child-appropriate remedies. Pets travelling in the vehicle or a pet-friendly cabin can also feel unsettled by motion — keeping them calm, comfortable, and not overfed before boarding helps. Our travelling with kids guide and pet travel guide have more on preparing younger or four-legged travellers for the crossing.