Adventure activity instructor Paul Grigg decided to undertake the grueling feat in an attempt to raise funds set to be used in supporting people affected by dementia.

"Both male and females, some who are old, but others who are even as young as their 40s, suffer from this debilitating condition," he said.

"It not only affects the individual, but has a profound effect on family and friends causing heartache and a huge financial and emotional burden."

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Mr Grigg set off on from Devonport on Saturday, July 2, before reaching his first stop at Greens Beach.

On Monday, July 4, he collected a sea kayak and started paddling with the tide to Launceston, a process that took two days due to changes in tidal direction.

From there he followed the Midland Highway, and by midday on Saturday, July 9, he had reached Symmons Plains on the way to his next destination - Bridgewater.

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It was from there Mr Grigg had planned to jump back into a sea kayak to finish the final leg of his 300-kilometre journey, which would see him end up at the Hobart Constitution Dock on Sunday morning.

However, after his friend - who was supposed to supply the kayak as well as paddle alongside him - experienced a car engine malfunction on the way there, Mr Griggs was forced to walk the final stretch.

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He arrived at the dock just after 10am on Sunday.

"I've pulled up pretty well, I suppose I'm used to it and now it's going to probably be a bit of the opposite as I'm expecting almost withdrawal symptoms from not walking each day," he said.

"Getting started is always the hardest part, but once you do, you'll be surprised what your body is capable of achieving when you put your mind to it."

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Mr Grigg said he felt a degree of personal satisfaction when he reached the finish line after initially being reluctant to publicise the event through fears he wouldn't complete it.

Mr Grigg had a fundraising goal of $5000, and so far has achieved almost half of that by bringing in $1200. However, donations are set to remain open for another week. Visit www.fundraising.dementia.org.au/fundraisers/paulgrigg.

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