A transatlantic has a specific packing challenge: you leave a cool European port in the morning, spend 7–9 sea days where temperatures swing, and end in somewhere that could be 40°F or 80°F. Plus formal nights. Plus limited laundry. Here's what works.
The system
Layering pieces
Two pairs of merino wool pants (don't wrinkle, don't smell)
Three merino base layers (short and long sleeve)
One light fleece
One packable shell (wind + rain)
Daywear
Two swimsuits (rotate so one's always dry)
Cover-up or sundress
Two pairs of shorts or casual pants
One cardigan or light jacket
Formal night
Most transatlantics have 2–3 formal nights. The dress code varies — "formal," "semi-formal," or "chic" depending on the line. Check your cruise line's specifics. When in doubt:
Men
Dark suit (can serve 2–3 nights)
Two collared shirts
One tie
Dress shoes (one pair)
Women
One cocktail dress + one long dress
Wrap or shawl (formal venues over-air-condition)
Small evening bag
Dress shoes — flats or low heels, ship decks are uneven
Everything else
Passport
Cruise documents (printed + in app)
Medications (2 weeks' supply minimum, in carry-on)
Formal outfit for gala nights
Evening shoes
Walking shoes (you'll log miles on the promenade)
Lanyard or wristband for room key
Power strip / multi-outlet (staterooms have 1–2 outlets)
Over-the-door organizer (bathrooms are tiny)
Highlighters for marking the Daily program
Motion-sickness preventative
Laundry pods (some ships have coin-op laundromats)
Small flashlight
Sunscreen + after-sun
Binoculars (crossings have wildlife)
What NOT to bring
FAQ
How many formal outfits?
2–3 is enough even for a 14-night crossing. Swap shirts/accessories to vary the look.
Can I do laundry on board?
Depends on the line. Princess, Holland America, and Regent have free self-service laundry; Carnival and Royal charge per bag; Norwegian has paid self-service.
What about a plug converter?
Yes. Most ships have US outlets but European lines have EU. Bring a universal adapter just in case.
How much carry-on?
Enough to survive 48 hours if checked bags are delayed. One change of clothes, toiletries, meds, swimsuit.