Familygoboston: From the Galapagos Explorer II website: We suggest wearing informal clothes during the day, however in order to maintain a spirit of casual elegance, during dinner we recommend a more formal dress code. Shorts, baseball caps, or sandals are not allowed during dinner.
Bathing suites are only allowed in the Jacuzzi area, a sarong or shorts are preferred in the ships public areas.
We recommend wearing light clothes when you visit the islands. Comfortable walking shoes appropriate for lengthy treks, a pair of sandals / TEVAS (with Velcro for wet landings) cotton shorts or pants or any other light fabric.
Cotton shirts with long or short sleeves. Hats or baseball caps due to the intense sun on the islands, bathing suits, windbreaker jackets and sweaters during the cold and dry (drizzly) season from July to December.
It also says in What to Bring: Casual Outfits for dinner (shorts & sneakers are not allowed).
I'm thinking capris, nice jeans, polo shirts, and flats would be fine.
Karen