US Navy Photo. JPALS tactical prototype
The Navy has already chose Joint Precision Approach & Landing Systems (JPALS) and BreakingDefense reports Raytheon is offering it to the Air Force and Army. Perhaps the Coast Guard should take a look. Like the Navy, the Coast Guard operates aircraft from moving ships, with perhaps even more “pitch, roll, surge, sway, heave, yaw, and translation”
JPALS fills the role of a TACAN, giving bearing and range to the landing area, but does it with much greater accuracy, directing the aircraft to a 20 cm (7.8″) square area, using differential GPS. It does it all in any weather and zero visibility with very low probability of intercept and in an encrypted format by data link, minimizing the need for radio communications.
Every time we turn on TACAN we broadcast the position of ship.
Potentially it can provide a autonomous recovery for aircraft and UAVs.
“What’s more, Raytheon is finishing development of a capability for JPALS to take over the flight controls and bring the aircraft in for an automated landing with no input from the pilot – or potentially with no pilot on board at all. That is why the Navy has contracted with Raytheon to put JPALS on its future MQ-25 carrier-based drone.”
Maybe our over-the-horizon boats could use it too.
Chuck Hill's CG Blog 
JAPALS is totally dependent on GPS signal, so question if GPS jammed, not too difficult as North Korea has been jamming wide areas of South Korea, what use is JAPALS.
GAO quoted program unit cost of $56.37 million as of 10/2016.
True and a good reason to have eLORAN, but we don’t have eLORAN yet and we are unlikely to see jamming in normal ops.
While development costs are significant, I doubt the equipment costs will be beyond our reach as the system becomes more common.