Here it is, directly from the Norfolk Constabulary:
Water safety
“When the weather is fine, then you know it’s a sign for messing about on the river.”
Picture the scene. The sun shines bright. The blue skies stretch out above without a cloud in sight. The nearby river glistens with rays of the sun. The sound of wildlife is interspersed with the sound of laughter – of friends or family sharing a drink and conversation… Welcome to Norfolk and the vast beautiful waterways that make up Norfolk’s national park – the Broads.
Yes, when the weather is fine, you know it’s a sign to head to the Broads. But whereas messing about on the river can be a fun day out, to ensure that your experience is enjoyable and one that leaves you only with fond memories, please follow the safety tips below, because ‘‘if you take our advice there’s nothing so nice as messing about on the river.’
Please wear your lifejacket / buoyancy aid at all times whilst on the boat or near the water’s edge
On a hot day, the water may look an inviting place to cool down, but remember the Broads is unsuitable for swimming in. The colder temperatures, along with underwater plants and fast currents provide unseen obstacles that can endanger the life of anyone entering the water
Never enter the water to get someone out - reach, or throw a rope or anything that will float
Keep an eye on everyone on board, particularly children, and avoid sitting on the front of the boat Alcohol and water can be a dangerous mix. The risk of falling into the water increases with alcohol consumption. Remember it is illegal to navigate a vessel under the influence of drink or drugs and there are hefty fines for those that do