A pensioner's heading off today on a 4,000 kilometre couch-surfing walk around the coast of Ireland.

Retired lecturer Dr Marty Holland is relying on strangers to put him up for the night during his epic trek.

It's all in aid of the Irish Cancer Society.

Marty says he's been inspired to take on the challenge by the death of two close friends from cancer.

The 65 year old admits he has mixed emotions as he sets off:

Anyone who wants to offer Marty a couch for the night can email CoastForCancer@Gmail.com