NAVD88 depth (Meters) - EPSG:6357

WKT

VERTCS["NAVD88_depth", 
	VDATUM["North_American_Vertical_Datum_1988"], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", -1.0], 
	UNIT["Meter", 1.0]]

WKT2

VERTCRS["NAVD88_depth", 
	VDATUM["North_American_Vertical_Datum_1988"], 
	CS[vertical, 1], 
	AXIS["Gravity-related height (H)", down, 
		LENGTHUNIT["Meter", 1.0]], 
	ID["EPSG", "6357"]]

Data from @esri/proj-codes

{
  "wkid": 6357,
  "latestWkid": 6357,
  "macro": "PE_VCS_NAVD88_D",
  "name": "NAVD88_depth",
  "wkt": "VERTCS[\"NAVD88_depth\",VDATUM[\"North_American_Vertical_Datum_1988\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",-1.0],UNIT[\"Meter\",1.0]]",
  "wkt2": "VERTCRS[\"NAVD88_depth\",VDATUM[\"North_American_Vertical_Datum_1988\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",down,LENGTHUNIT[\"Meter\",1.0]],ID[\"EPSG\",\"6357\"]]",
  "description": "NAVD88 depth (Meters)",
  "authority": "EPSG",
  "version": "8.2.7(10.3.1)",
  "deprecated": "no",
  "areaname": "North America - Mexico and USA - onshore",
  "extent": {
    "slat": 14.51,
    "nlat": 71.4,
    "llon": 172.42,
    "rlon": -66.91
  }
}