Two zooms cover almost everything: one general purpose or wide zoom for landscapes, people, shipboard scenes and close wildlife, and one telephoto zoom for distant wildlife, birds and whales. On full frame that's often something around 24 to 70mm or 24 to 105mm paired with 70 to 300mm, 100 to 400mm or similar. It's a starting shape rather than a formula.
A single broad-range zoom is one of the smartest expedition choices going. It removes lens changes, keeps the kit light and lets you react. The compromises, a smaller maximum aperture and softer extremes, matter less in the abundant summer light.
You can also let your phone be the wide camera while the dedicated body carries the telephoto. That works better than people expect.
Bring less than you think. Everything has to go through airports, down ship stairs, into Zodiacs and across beaches, and every extra item is another thing to protect, clean, charge and keep track of. If the weight puts you off carrying the camera, the kit isn't helping you.
Most people can leave the tripod at home. It's hard to use on a moving ship or Zodiac, it takes space, it's a trip hazard, and it may be restricted at some sites. Plenty of tripods never leave the cabin.