MSL depth (Intl Feet) - EPSG:8051

WKT

VERTCS["MSL_depth_(ftIntl)", 
	VDATUM["Mean_Sea_Level"], 
	PARAMETER["Vertical_Shift", 0.0], 
	PARAMETER["Direction", -1.0], 
	UNIT["Foot", 0.3048]]

WKT2

VERTCRS["MSL_depth_(ftIntl)", 
	VDATUM["Mean_Sea_Level"], 
	CS[vertical, 1], 
	AXIS["Gravity-related height (H)", down, 
		LENGTHUNIT["Foot", 0.3048]], 
	ID["EPSG", "8051"]]

Data from @esri/proj-codes

{
  "wkid": 8051,
  "latestWkid": 8051,
  "macro": "PE_VCS_MSL_D_FT",
  "name": "MSL_depth_(ftIntl)",
  "wkt": "VERTCS[\"MSL_depth_(ftIntl)\",VDATUM[\"Mean_Sea_Level\"],PARAMETER[\"Vertical_Shift\",0.0],PARAMETER[\"Direction\",-1.0],UNIT[\"Foot\",0.3048]]",
  "wkt2": "VERTCRS[\"MSL_depth_(ftIntl)\",VDATUM[\"Mean_Sea_Level\"],CS[vertical,1],AXIS[\"Gravity-related height (H)\",down,LENGTHUNIT[\"Foot\",0.3048]],ID[\"EPSG\",\"8051\"]]",
  "description": "MSL depth (Intl Feet)",
  "authority": "EPSG",
  "version": "9.2(10.8.0)",
  "deprecated": "no",
  "areaname": "World",
  "extent": {
    "slat": -90,
    "nlat": 90,
    "llon": -180,
    "rlon": 180
  }
}