TWO giant jellyfish, each the size of a "head," have been seen swimming underneath Boscombe Pier.

Holly Marschall first spotted the two jellyfish on Tuesday, September 20 in the evening before getting a "clearer view" of them again the next morning.

Holly was out on a routine daily walk on Tuesday with her students when the marine animals were first spotted. 

She works for Swrac a training provider in Boscombe, and said the students were "shocked" at what they saw and commented that they were "huge."

Holly said: "I had never seen anything like it before. The students were shocked and thought it was amazing. 

"It's different to seeing them at the aquarium, they were probably about the size of my head by the looks of them.

READ MORE: Jellyfish spotted in Poole Park Lake

Bournemouth Echo: Picture by: Holly MarschallPicture by: Holly Marschall (Image: Holly Marschall)

"They were quite far down so it's hard to say exactly but they were pretty big, about the size of my hands.

"They were just floating and swimming around, it was really unusual to see them there.

"There must be a family under the pier because they kept swimming under there."

A number of barrel jellyfish have been spotted in the sea and washed up on beaches along the Dorset coast over the years.

READ MORE: Huge barrel jellyfish found washed up on the shore in Poole

Dorset Wildlife has said to look but don't touch - jellyfish are capable of stinging even when stranded dead on the shore.  Remember to keep dogs away too. 

A large barrel jellyfish can weigh up to 35kg; because of their size they are also known as ‘dustbin-lid jellyfish’.

They are most often seen between May and October.

Dorset Wildlife says that the presence of the barrel jellyfish in our waters means we could see some leatherback turtles, which feed on jellyfish. Ocean sunfishes could also be spotted.