Celebrate Your Child’s Special Day at Herts Young Mariners Base!

Turn your child's birthday or signifcant event into an unforgettable outdoor adventure. At Herts Young Mariners Base, the great outdoors becomes the ultimate playground. Our Adventurous Activities Birthday Packages are packed with action, laughter and excitement—perfect for kids who love to explore, splash, and try something new.

From thrilling watersports to land-based activities, our experienced instructors lead the adventure while you relax and enjoy the smiles, high-fives and muddy trainers. It’s all about fresh air, teamwork and fun—away from screens and straight into nature.

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Adventurous Activity Party Packages

Climbing Party – Reach New Heights

A climbing party is the perfect way to celebrate! Children aged 8+ will learn the basics of climbing and safety with guidance from our expert instructors.

Once confident on the wall, they’ll take on fun challenges and obstacle routes, building strength, teamwork, and confidence—all while having a blast.

Age: 8+ years
Duration: 90 minutes
Packages (Catering included)
£300 per party package of 15 children – (Additional children £20 per child)

Ideal for adventurous kids who love challenges, fun, and reaching new heights!

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Caving Party – Explore the Underground

A caving party is an exciting way to celebrate! Children aged 8+ will learn basic caving techniques and safety tips from our expert instructors.
They’ll then explore tunnels and hidden passageways, discovering the thrill of adventure underground while working together as a team.

Age: 8+ years
Duration: 90 minutes
Packages (Catering included)
£300 per party package of 15 children – (Additional children £20 per child)

Perfect for kids who love exploration, adventure, and a little mystery!

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Paddleboarding Party – Fun on the Water

A paddleboarding party is the perfect way to celebrate! Children aged 8+ will learn how to balance, paddle, and glide across the water with tips and guidance from our expert instructors.
After mastering the basics, they’ll take part in fun challenges and games, enjoying the thrill of adventure and the fresh outdoors. Splashing is all part of the fun, so get ready for laughter and smiles all around!

Age: 8+ years
Duration: 90 minutes
Packages (catering)
Price: £300 per party package of 15 children – (Additional children £20 per child)

Perfect for water-loving kids looking for fun, active, and memorable birthday celebrations!

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Kayaking & Canoeing Party – Paddle, Explore and Celebrate

Make their birthday an adventure on the water! Children aged 8+ will learn the basics of kayaking and canoeing, gaining confidence, balance, and paddling skills with guidance from our expert instructors.
Once they’ve mastered the techniques, they’ll take part in fun races, team challenges, and water-based games, enjoying the thrill of the lake in a safe, supervised environment. Splashing, laughter, and memories are all part of fun!

Age: 8+ years
Duration: 90 minutes
Packages (catering Included)
£300 per party package of 15 children – (Additional children £20 per child)

Perfect for kids who love water, adventure, and unforgettable birthday fun!

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Archery Party – Aim for Fun

An archery party is a thrilling way to celebrate! Children aged 8+ will learn the basics of archery and safety from our expert instructors.
Once ready, they’ll take part in fun target challenges and friendly competitions, testing their aim and focus while enjoying outdoor adventure. Perfect for building confidence, concentration, and a sense of achievement!

Age: 8+ years
Duration: 90 minutes
Packages (catering included)
Price: £300 per party package of 15 children – (Additional children £20 per child)

Perfect for kids who love fun, adventure, and testing their skills in the great outdoors.

Book now

Additional Information

Where possible, please arrive 15 minutes before the time on your booking confirmation
Late arrivals may not be able to take part in the activity and will not be refunded

Participants aged between 8 – 16 years must have their legal parent/guardian remaining on site at Herts Young Mariners Base for the duration of the session, with one parent/guardian to every four children (max)

All participants must be aged 8+ and individually weigh under 18 stone
All participants must wear closed toe shoes - no sandals, flip flops, or heeled shoes are permitted
All participants must wear a minimum of shorts and a t-shirt whilst on site
Parents/guardians must sign a Flat Water Declaration Form online prior to arrival and supervise their children under 12 at all times

Catering included in your party package

As part of our birthday party packages, catering is provided by the YHA – Youth Hostel Association, with four delicious menu options to choose from. We allow an additional 45 minutes for food and celebration, served in an exclusive area overlooking the lake, giving the kids a chance to relax and chill out after their activity.

Chicken Nuggets & Chips
Pizza – with a choice of toppings to suit every child
Vegetarian Option
Additional Options – please contact us in advance for any special dietary needs

Additional snacks or drinks are available to purchase from our HYMB Snack Bar