Complex sentence: To prevent water from ruining the whale's electronics, the modelmakers sealed every individual mechanical component rather than attempting to waterproof the entire whale, and added balloons and lead weights to achieve the proper balance and buoyancy.
Split into simpler sentences: To prevent water from ruining the whale's electronics, the modelmakers sealed every individual mechanical component rather than attempting to waterproof the entire whale. Balloons and lead weights were added to achieve the proper balance and buoyancy.