When traveling by air, it is prudent to put your optics in your carry-on luggage. First, there is the ever-present concern about theft, particularly if your birding destination is international and includes small charter flights, regional carriers, or alternative transportation modes in the itinerary. Also, luggage compartment holds in jet aircraft are not pressurized. If the air pressure inside your binoculars or spotting scope exceeds the compartment pressure, the internal seals may rupture, with the result that your “waterproof” instruments no longer merit this description.
Tripods may be checked. In fact, some airlines won’t allow you to carry a tripod on the plane. The standard is maddeningly capricious. I once traveled with a birder who was allowed to carry on his tripod when we boarded in the United States, but on our return flight from South America (on the same carrier), he was required to check it. For added inconvenience, this determination was made at security, not at the check-in desk. It’s best to contact your carrier in advance to ascertain their standards.
When buying tripods, choose a model that folds to suitcase size. When packing in soft luggage, bracket the head with your shoes for protection. If you can carry the tripod on the plane, place electrical tape over tightening knobs. Vibration may cause them to loosen and fall off in overhead luggage compartments—a vexation not commonly noticed until you try to set up in the field. By that time, your tightening knobs and washers are on their way to Singapore. From experience, I generally carry a supply of spare tightening knobs in my toiletry kit anyway, as well as a roll of strong adhesive tape.
The merits of bringing small, lightweight, backup binoculars will become apparent when your primary glass goes thunk onto the deck of your cruise ship or onto the airport tarmac. Upon exiting a bush plane in the Arctic, I once got my foot tangled in the safety harness and did a header, binoculars first, onto the packed cobble of a river bar. Accidents happen, and when you are hundreds of miles from an optics dealer and at the beginning of a 10-day raft trip through the Arctic National Wildlife Refuge, you are on your own. Another possibility: It is likely that one of your traveling companions will have binocular issues, and you can save the day with your trusty backup. If you are also a butterfly watcher, consider the merits of bringing an alpha birding glass and a butterfly (super-close focusing) backup. Despite manufacturer claims, few instruments excel at both close and distant viewing. It’s physics, boys and girls, and you can only bend the laws so far before performance suffers at one end of the scale or the other.
And it goes without saying that, if you are a globe-trotting birder, rugged premium binoculars are a must. When planning that trip of a lifetime to Antarctica, the last place to cut costs is optics.