Monty's wild about the sea; TVChoice.
So he swapped life as a Marine for one of a marine biologist, and has become one of TV's most amiable experts in the field.
He has certainly proved his worth in this series, which comes to an end this week.
For newcomers, he and his dog Reuben have been living on the west coast of Ireland for six months, monitoring and observing the area's rich sea life.
Some of the largest animals on the planet migrate through the waters at Connemara and this is a rare opportunity for Monty to explore the extraordinary creatures that inhabit these shores. So, what was the biggest challenge about making the series? "Strangely enough it's a combination of making a television programme and trying to do some decent work scientifically. It's one of those sort of unseen things of any show," explains the host while promoting The Monty Halls' Great Escapes DVD box set that hits stores on Monday.
He says people have commented that there doesn't seem to be a lot of science going on.
"The reason is that a huge amount of time was spent just patrolling the coast, and it's not great telly - a bloke, alone in a boat, patrolling for hour after hour," he smiles.
"So that was a real challenge - to try to make a vaguely entertaining television programme, but layered on top of that was trying to do some decent work for the scientific and conservation community that I was working for there.
"No one will believe me when I say this, but it's pretty knackering actually, because you patrol all day in the boat and then you come back and have to shoot stuff for the TV show."
New vocation: Monty Halls swapped life as a Royal Marine for life as a marine biologist.