US offshore vessel owners posted some of the worst declines among maritime-related stocks this week as the sector continues to suffer from uncertainty.

Tidewater and GulfMark Offshore both saw their shares plummet below the key $1 mark, the minimum share price to keep a listing on New York's stock exchanges.

Houston-based GulfMark was the week's worst performer among US-listed shipping and offshore vessel shares, according to an analysis by TradeWinds.

Nearly