Adult Outdoor Activities | Herts Young Mariners Base

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Great Adult Outdoor Activities

At HYM, we know that adventure and connection are essential at every age — especially for adults seeking more from their time outdoors. Our Adult Outdoor Activities blend invigorating physical challenges with restorative moments in nature, ideal for professionals, fitness enthusiasts, and outdoor lovers. Hike scenic trails, master kayaking, explore mountain biking, or unwind with sunrise yoga by a tranquil lake. Every experience fosters personal growth, camaraderie, and a deeper appreciation for the environment. With experienced guides ensuring safety and encouragement, our programs are designed to help you reconnect with nature, recharge mentally and physically, and forge lasting friendships along the way.

School group enjoying fun water based activities in Hertfordshire.

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How it works

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1. Choose Activity

We have lots of fun activities for all ages.

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2. Book Your Session

Book your session online or call us for large groups.

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3. Have Fun & Get Fit

Enjoy your activity, become healthier and make new friends.

Book Your Session

Google Reviews

Why choose Herts Young Mariners Base

Experience

63+ YearsOf Outdoor Activities

At HYMB our instructors hold the relevant qualifications and are checked & tested regularly.

Trust

Based on 80 reviews

We have over 100 Google reviews.

Our Promise

Better self-confidence and social interaction.

British Fencing - HYMB

Paddle UK - HYMB

Freaquently Asked Questions

▶Where is Herts Young Mariners?

HYMB is in Cheshunt, Hertfordshire. We are approximately 10minutes from Junction 25 on the M25 or a 2 minutes walk from Cheshunt train station. Click here to view map

▶What to Bring?

Please bring a change of clothes if you are doing a combination of land-based and water-based activities a towel and a bag to put wet & muddy clothes in. You are required to wear footwear at all times, and they need to be enclosed. Please do not wear FLIP FLOPS or CROCS Some activities like Caving require you to wear long sleeved tops and trousers. Please also bring any medication that is required and sun cream for those sunny and hot days.

▶Safety?

All staff are DBS checked All Instructors are first aid trained. All Instructors are qualified for the activities that they will be running. All participants will be supplied, fitted and checked with the relevant safety equipment. While on or near the water all participants and helpers will need to wear Buoyancy aids or Lifejackets. While Climbing you will be issued with Helmets and Harnesses. While Caving you will be issued with Helmets. You will be required to wear long sleaved tops and trousers.

▶Accessibility?

There is easy access to the centre. There are hoists in the 2 disability rooms and a waterside hoist to assist participants on to the water if required.

▶Is there accommodation?

We do not have any indoor Accommodation but there is the Lee Valley YHA next doors that groups use. There is Camping facilities on site if of interest for groups doing DofE expeditions or youth groups camping.

▶How do I contact you in an emergency?

If you need to contact HYMB between the hours of 9am and 5pm you can call the office on 01992 628 403 If you are camping on site and you require assistance while out of hours, you will be provided with a mobile number to contact us for assistance.

▶Can I participate if I have a Medical conditions?

We encourage all participant to take part in the activities and we can adapt the activity to suit the groups abilities or requirements. We do ask that you make sure that our staff are aware of any special needs that the members of the group have before the visit. This is so we can make sure everything is in place for the day.

▶What happens if there is bad weather?

The majority of activities are unaffected by the weather. If the instructor in charge feels that activity is unsuitable for those conditions, then we can change to something more suitable following a discussion with the group leader. If there is thunder and lighting all participants will be bought indoors until it has passed. If you have any concerns about the weather, please contact the office 01992 628 403

▶Does HYMB have insurance?

HYMB has a £10 million public liability insurance. Any claim for compensation will be referred to the underwriters. We strongly recommend that you take out suitable insurance cover against cancellation, accidental injury and loss for damage to personal property whilst visiting the centre.

▶How do you maintain Safety?

At HYMB we regularly monitor staff on sessions to maintain the highest standards of safety and provide extra training if Required. All safety equipment is checked on a regular basis and before each session, and that is fits the Participant correctly. HYMB is inspected annually by AALA (Adventure Activity Licencing Authority) and the RYA (Royal Yachting Association).

▶On site Facilities?

At HYMB we have full changing and shower facilities with 2 rooms that have hoists. There are a very limited number of Lockers available. Plenty of parking.

▶Is there accommodation?

▶Is food provided?

Food is not provided. We suggest that if you are here for the whole day that you bring a packed lunch and plenty to drink.