Chris Hemsworth has really not had such a great time filming his latest movie 'In The Heart Of The Sea'. As much as it must've been an epic film to shoot; lost at sea and playing a character that's slowly going out of his mind; it wasn't without it's gruelling compromises.

Chris Hemsworth in 'In The Heart Of The Sea'Chris Hemsworth looked a lot different before his weight loss

It's the story that inspired 'Moby Dick', and one that gets considerably more gruesome as it progresses. 'In The Heart Of The Sea' documents the adventures of the crew of Essex; a whaling ship that was sunk by a sperm whale in 1820 leaving the crew stranded in the middle of the sea. Hemsworth plays First Mate Owen Chase, but it seems that it's become his most challenging role so far giving that he had to lose weight for the role and faced very real dangers. Here's just five main reasons he's not doing a film like that again in a hurry:

1. The danger - He became genuinely ship-wrecked at one stage. Accompanied by his wife Elsa Pataky and daughter India, the boat they were sailing on in the Canary Islands (where the film was being shot) one evening hit a reef and sent the couple flying. 'I went eight feet in the air and my daughter, thankfully, was sitting on the floor of the boat playing with something so she scratched her knee and started screaming', he told Who magazine. 'My wife kinda flew over me'. Though no-one was seriously hurt, it was certainly a terrifying experience for the family and the others aboard.

2. The hunger - Hemsworth and his co-stars were forced to cut their calorie intake week by week in order to become gradually skinny enough to fit the roles of ship-wrecked sailors. 'By the last couple of scenes when we were at our skinniest, we were on 500 or 600 calories a day', he revealed, admitting that it was important to take extreme measures in order to commit to the role. 'You're living and breathing that experience as much as possible.' The average daily diet consisted of one meal a day, which was typically just fish and salad. He has since insisted that the weight loss was much harder than bulking up for roles like 'Thor'.

More: Hemsworth isn't the only actor to devote his body to the big screen

3. The exhaustion - The lack of food combined with the heat of the Canary Islands and the intense scenes meant that the cast's tiredness was often overwhelming. 'Sometimes when 'cut' was called you would literally pass out from exhaustion', Hemsworth claimed in an interview with Graham Norton. 'It was the most physically challenging thing to do'.

4. The heat - It turns out it wasn't exactly comfortable shooting in intense heat for many reasons, including the costume situation. After all, that wasn't his real beard. 'It's hot and sweaty and you've got beard glued on to your face and you can't really move', he said. 'Every time you do it would open up and you'd have to glue it back on.'

5. The damp - It's never a particularly pleasant feeling to have to work while sopping wet from head to foot, but the effect was magnified a thousand times on set with Hemsworth already feeling hungry, tired and hot. 'I feel like we were wet for 90 per cent of the film and uncomfortable', he told London Live. ' [I'll] maybe not do [a movie] in the water for a while.'

Watch the trailer for 'In The Heart Of The Sea' here: