Seasickness is not extremely common on the whale shark portion of the tour, because the encounter takes place in Saleh Bay during the early morning when the water is usually very calm. Most guests find the boat ride to and from the whale shark area to be gentle and stable. However, the longer journey between Lombok and Sumbawa includes a ferry crossing and open water travel that can affect sensitive travelers, especially if the seas are slightly choppy or if the ferry ride coincides with movement that triggers your inner ear.
If you know you are prone to seasickness, it is a good idea to take motion-sickness medication before the ferry ride and the boat transfers. Sitting in fresh air, keeping your eyes on the horizon, and avoiding heavy meals right before travel are also effective strategies. The team is familiar with guests who experience seasickness and will do their best to position you in the most stable part of the boat and keep you informed about how long each leg of travel will last.
The overnight structure of the tour actually helps with seasickness, because you are not rushing through the entire journey in one exhausting day. You have time to rest, eat lightly, and recover between travel segments. If you do feel queasy, let your guide know immediately — they can offer practical advice, help you get to fresh air, and adjust your seating. For most travelers, any mild discomfort passes quickly, and the reward of swimming with whale sharks makes it more than worthwhile.

