Just like how a Golden Behemoth could leverage on the power of the earth, Elder Zumar would be able to use the Divine Sea Pillar as a medium to communicate with the ocean and obtain its power while he was in the ocean. It was almost equal to having infinite mana.
However, for Lin Li, the Divine Sea Pillar was much less attractive because the debris of the stars, Polar Snow, that he owned contained the purest elemental laws of water, which were much more profound than the oceanic laws of the Divine Sea Pillar. As for the function of suppressing the wind and waves to ensure the safety of the ship, it was redundant because he felt that some ordeals and tribulations were necessary for personal growth. No matter how excellent a fleet might be, it would be useless if it hadn't experienced any dangerous weather or other adverse conditions at sea.