And with the successful first sea trials of two new, 590-foot-long fleet oilers — tanker ships designed to keep other vessels fueled, or “replenished,” while sailing long distance — the PLAN could soon be able to deploy all this new hardware beyond coastal waters.

“Replenishment vessel construction rate will be a particularly revealing barometer of the PLAN’s future expeditionary intentions,” wrote Andrew Erickson, an analyst at the U.S. Naval War College. The more new oilers, the farther China will be able to send its new capital ships. Without underway replenishment, most naval vessels can travel only a few thousand miles; with fuel top-offs, they can circle the globe.