With all diligence, the commission shall:

1. (a) Proceed to cause proper surveys to be made of any harbor intended to be improved, developed or protected.
2. (b) Collect, compile and preserve all proper data and information concerning the harbor, and the necessity, advantage and benefit to be derived by its improvement, development or protection.
3. (c) Carefully investigate and examine the condition of the harbor.
4. (d) Ascertain the best, most feasible and practical plan and system of improvement, development or protection to be used and employed, and its cost.