"Therefore, on the BB, the best way I could improve movement in water would be to add a bulbous bow on the ship, flame spray everything below the waterline with a non-carbon/iron metal to make it very smooth and add high skew propellers." Richard Landgraff, 10/21/2013
In addition to the on-going evaluation of various re-engining schemes, the ICeBeRG (Iowa Class Battleships Re-engining Group) has now decided to investigate potential hydrodynamic improvements that might be worth backfitting into BB-61 class ships.
The focus of such hydrodynamic improvements is speed (top speed & max cruise speed) and not fuel consumption, since replacing the existing steam plant with diesels will by itself produce ample fuel savings (see here).
Maximum cruise speed desired is 18 knots (threshold) / 20 knots (objective). Depending on the re-engining scheme, top speed @ 100% MCR is comprised between 22 knots and 28 knots.
One of the hydrodynamic improvements envisioned at present is the addition of a bulbous bow projecting further forward of the fore perpendicular. It's been observed that adding a bulbous bow or modifying its shape is fairly common in the civilian sector.
Some comments already made on bulbous bows in other threads will be re-posted below.