Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Ocean has been climbing in recent years. All-time it's been given to 8,233 U.S. babies, the 791st most common name by sound today, peaking at 855 in 2022, with 720 in 2025.
Ocean has no common alternate spellings by sound.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).