In both cases, the nearest emergency towing vessel was days away from helping.
The appeal comes after the 53,000-tonne MV Eleanor D broke down 150 miles west of the Hebrides last week. It took five days for help to reach her.
Heavy seas and force-eight gales risked blowing the MV Wilson Gdynia bulkcarrier onto rocks after she lost rudder control between Barra and Tiree on Saturday.
Desperate to prevent an oil spill if she grounded, her captain used her bow-thruster to roughly steer her on a staggered course away from land.
Barra and Tobermory lifeboats stood watch, ready to take the eight crew off the stricken ship, if required.
The 88-metre long vessel was left drifting off the Western Isles before a tug finally arrived yesterday after being chartered from Aberdeen. She was towed to Belfast for repairs.
In neither case was the government-chartered tug, MV Herakles mobilised from her station in Orkney.
Council leader Angus Campbell said the absence of emergency tug cover in the west coast concerned coastguards.
He said: "The time delay in the boat arriving from that distance away, in addition to the severe weather, highlights how vulnerable the west coast is.
"We would call on the UK Government to reconsider the provision of a second tug based in the western waters of Scotland to reduce the risk for mariners and the environment in what is a major shipping area."