Viking boat tactics....

[Imperial Dave]

https://www-bbc-co-uk.cdn.ampproject.org/v/s/www.bbc.co.uk/news/articles/c1l4y0pr70go.amp?amp_gsa=1&amp_js_v=a9&usqp=mq331AQGsAEggAID#amp_tf=From%20%251%24s&aoh=17296149193708&csi=0&referrer=https%3A%2F%2Fwww.google.com

Makes sense to me...

[Duncan Head]

I thought the use of portages was well established, but maybe that was just the sagas.

[Jim Webster]

From memory the only Tarberts I know are where you could have a portage. And it was a well established technique the Vikings used in other places

[Imperial Dave]

Not so much new news as a (re)confirmation of likelihood of MO then

[tadamson]

Not news at all...

There are notes in one of the Glasgow museaums (they used to be in the transport museaum when it was in the Kelvin Hall) from the building of the Crinan Canal that talk about following the portage route.
To be fair, there is evidence that there was a portage route here long begore the Vikings.