Hot Water Beach is one of those Coromandel days out that sounds made up until you're standing in it. Geothermal water rises up through the sand, and if you dig a hollow in the right spot you get your own steaming hot pool, out in the open with the surf a few metres away. It's genuinely lovely, and it's free to do. But it comes with one non-negotiable catch, and a serious safety warning, so it pays to read this before you load the car.

The catch is the tide. The hot patch sits low on the beach, and for most of the day it's underwater. You can only dig around low tide, so the whole trip has to be planned around the tide chart for that day, not around when it happens to suit you. Get the timing right and it's easy. Turn up at high tide and you'll be standing on a normal beach wondering what all the fuss is about.

What it actually is

Two underground fissures feed hot water up through the sand near the southern end of the beach. It's the real thing, not a built pool. The water coming out can be scaldingly hot, so what you're really doing is digging a small basin and letting cooler seawater wash in to bring it down to a temperature you can sit in. When you find the sweet spot, you dig a pool, bank up the sand walls to keep the sea out a bit, and settle in. On a busy day you'll be one hot pool in a whole row of them.

The tide window: check this first

You can usually dig for roughly two hours either side of low tide, which gives you a window of about four hours. Outside that, the spring is covered by the sea and there's nothing to do.

So the first thing to sort, before anything else, is the low-tide time for your chosen day. Search "Hot Water Beach tide times" or use a New Zealand tide chart (Tairua or Whitianga tides are close enough) and note the low-tide hour. There are two low tides most days, so pick whichever suits you. A low tide that lands mid-morning or late afternoon is ideal. A low tide at 3am is less fun. Build your whole day around that number and you'll be fine.

Getting there and parking

The beach is about 12 km southeast of Whitianga, and only around a 10-minute drive from Hahei. Coming down State Highway 25, turn off near Whenuakite onto Hot Water Beach Road (it's well signposted) and follow it to the coast.

The main car park is at the southern end, closest to the hot spot, and it's pay and display, roughly $4.50 an hour or about $29 for the day. There's a cheaper overflow car park (the Taiwawe or "bull paddock" area) at around $2.25 an hour, and a free option a bit further out that means a walk of a few hundred metres. Whatever you save on parking, do factor in that the money helps fund the surf lifesaving patrol here, which matters more than usual at this beach. There are toilets and cold showers at the main car park, handy for rinsing sandy legs afterwards.

Where to dig, and getting a spade

Head for the rocks toward the southern end of the beach. The hot patch is in the sand in front of and around those offshore rocks. The simplest way to find it is to walk out at low tide and feel the sand with your feet, or watch where everyone else has gathered. Warm sand means you're close. If you dig straight into the hottest spot it'll be too hot to bear, so start at the edges and let seawater mix in.

You'll want a spade. You can hire one for around $10 from the Hot Water Beach Cafe, Hotties Cafe, or the Hot Water Beach Top 10 Holiday Park near the car park. Bring your own if you have one. A decent spade makes a real difference; scooping with your hands or a bucket lid is slow going in wet sand.

What to bring

• Togs (swimwear) worn under your clothes, and a towel
• A spade, hired or your own
• Jandals or old shoes; the sand near the spring can be hot underfoot
• Sunscreen and a hat; there's no shade out on the sand
• Drinking water, especially in summer
• A rubbish bag, and please fill your pool back in when you leave

The safety warning: swimming and the rip

This part is important, so I'll be blunt. Hot Water Beach is one of the more dangerous swimming beaches in New Zealand. It has a strong rip current, particularly around the offshore rocks, and people have drowned here. The pull can be sudden and it doesn't care how strong a swimmer you are.

The signs on the beach advise not to swim within 50 metres either side of the offshore rocks, which is exactly the area you'll be digging in. Digging in shallow water at low tide is fine. Going for a proper swim there is not. If you want to swim, only do so between the flags set out by the Hot Water Beach Lifeguard Service, and only when they're on patrol, which is generally over the summer season and not year-round. If there are no flags out, treat the surf as unsafe and stay out of it. If you're ever caught in a rip, don't fight it; raise an arm to signal, float, and let it carry you out until it eases, then swim back at an angle. Keep a close eye on children the entire time.

The scalding-water caution

The water rising through the sand can reach around 64°C, which is hot enough to scald. Never plunge straight into a freshly dug hole or the hottest patch. Dig around the edges, let cool seawater flow in, and test with a hand or foot before you sit. If your pool is too hot, break a channel to the sea and let more water in. Watch small children closely near the hottest sand.

Best time to go, and crowds

Timing is dictated by the tide, but within that, early morning around a dawn-ish low tide is the quietest and often the most magical, with steam rising in the cool air. Sunset low tides are popular and busy. It's a year-round spot; winter can be wonderful, sitting in warm water while it's cold out, though the swimming risk is higher then because there's no patrol. Summer school holidays and public holidays get very crowded, with people jostling for the best patch, so arrive early in your tide window to claim a good spot.

Nearby

You're right by two of the Coromandel's best-known spots. Cathedral Cove and its famous rock archway are a short drive north via Hahei, and Hahei itself is a lovely beach village with cafes and a stunning stretch of sand. Many people pair Hot Water Beach with one or both, working the two-hour dig window around a walk or lunch nearby.

Plan your dig

• Check the low-tide time for your day first; plan everything around it
• Aim to be on the sand within two hours either side of low tide
• Bring or hire a spade (about $10 from the cafes or holiday park)
• Dig in front of the rocks at the southern end; feel for the warm sand
• Mix in seawater; the source water can hit 64°C
• Do not swim near the rocks; only swim between the lifeguard flags in season
• Fill your pool back in and take your rubbish with you

Frequently asked questions

When can you dig a hot pool at Hot Water Beach?
Only around low tide. You can usually dig for about two hours either side of low tide, giving roughly a four-hour window. At high tide the hot spot is underwater. Check the tide times for your specific day before you go, as low tide falls at a different hour each day.

Is it safe to swim at Hot Water Beach?
Swimming is risky. Hot Water Beach has a strong rip current, especially around the offshore rocks, and drownings have occurred. Signs advise against swimming within 50 metres of the rocks. Only swim between the flags of the Hot Water Beach Lifeguard Service when they are patrolling, generally over summer. If no flags are out, stay out of the surf.

Where do you get a spade at Hot Water Beach?
You can hire a spade for around $10 from the Hot Water Beach Cafe, Hotties Cafe, or the Hot Water Beach Top 10 Holiday Park near the car park. You can also bring your own. A proper spade makes digging in the wet sand far easier than using hands or a bucket.

Is Hot Water Beach free to visit?
Digging your own hot pool is free. You will usually pay for parking, though: the main car park is about $4.50 an hour or $29 a day, with a cheaper overflow car park and a free option a short walk away. Spade hire, if you need it, is around $10 extra.

More Coromandel guides

• Cathedral Cove
• The Pinnacles Walk
• New Chum Beach
• Karangahake Gorge