Orca said the “high density” marine wildlife areas seem to have shifted north to the Uig-Lochmaddy-Tarbert and the Ullapool-Stornoway routes – a trend first noticed last year.
On Uig-Lochmaddy-Tarbert, minke whale were spotted and 25 common dolphins swimming together in a “super pod”.
On the route between Ullapool and Stornoway, there was an occasion when 13 harbour porpoise were seen.
Spotted on the route at various times were common dolphin super pods numbering between 13 and 30.
The species, which hunt squid and fish including herring and mackerel, were also seen bow riding – swimming in groups in front of ferries.
However, the Oban-Castlebay route recorded the most species.
They included harbour porpoise, common dolphin, minke whale and grey seal.
On another route – Oban to Tiree – 30 sightings of harbour porpoise were seen across the survey.
These animals are described as shy and make a “chuff” sound when they come to the surface to breathe.
Orca said: “Very excitingly a pod of five orcas were seen on the Uig-Lochmaddy-Tarbert route.
“The most productive surveys were the July and October Ullapool-Stornoway surveys, where more than 100 animals were recorded on each survey.”
Other organisations also survey Scotland’s sea life, including the Hedridean Whale and Dolphin Trust and Whale and Dolphin Conservation.