The following is a summary of the safety instructions of the Finnish Canoeing and Rowing Federation and the Finnish SUP Association, accompanied by a few of my own observations.
You should choose a SUP board based on the conditions you intend to use it in and how experienced the paddle rider is. The so-called allround boards are suitable for everyone. The renters and sellers of the boards can guide you in choosing SUP boards. It is also a great opportunity if you can try different types of boards before making a possible purchase decision.

Dressing according to circumstances is wise. The need for a change of clothing depends on the length of the trip and the skills of the kayaker. In warm summer weather, it can be nice to take a dip in the water from time to time. In the coldest weather, a wetsuit or dry suit, as well as a hat, gloves and neoprene slippers are necessary.
On excursions, the landing points can be barefoot piers or sandy beaches, but also rocky or mudflat. In this case, footwear for water conditions protects and makes gait more comfortable.

On my first SUP summer, I bumped my bare leg into a rock clump hiding underwater when I staggered off a board in the shallows. I was able to heal an open wound on my tibia for many weeks. After that, I started wearing wetsuit pants on my most obvious rumbling trips.
Having a small bag of first aid supplies on the go isn’t necessarily a bad idea. For plaster and bandage needs, waterproofing should be taken into account. It is also a good idea to reserve repair supplies for the board for the excursions, unless you are on routes that you can easily get off anywhere if necessary.

Leash should not be left lying in the sand. It’s called a SUP paddleboarder’s seat belt. Without runaways, the board can bounce quite far if you fall unexpectedly. The surf easily takes the board with it. The runaway strap has proven its competence many times.

A flotation vest or, for children, a life jacket is also a necessary piece of clothing. Swimming skills are also important. There are different vests for those paddling with different equipment. A vest with spacious front pockets may not be the most convenient for SUP paddlers, especially if you are trying to sink back onto the board. At the very least, kayakers should attach a whistle or other audible warning device to their vest. In low light conditions, white light is advised.

It’s a good idea to pack your phone in a waterproof bag and make sure that the location app (e.g. 112 Suomi) works and that there is enough power. It’s a good idea to take a power bank with you on longer trips.

All even slightly more important items should be carefully attached to the board or to yourself with some trick. In my first summer of kayaking, I lost my smartwatch to the bottom of the lake. It really floated for a while. I can’t say exactly for how long.
The instructions recommend learning the correct paddling technique and participating in a SUP beginner’s course. Paddleboarding isn’t difficult, but there are plenty of tricks to help you get started and progress. The easiest way to learn them is under direct guidance. From the Youtube videos about the mistakes most typically made by beginner SUP paddlers and how to correct them, I have learned many tricks.
It is recommended to go on canoeing trips with company. Even then, but especially if you are going on a trip alone, it is a good idea to inform someone close to you of the route and return time or if there are changes in plans.
Paddling in harbour areas, boat lanes and heavily trafficked areas is recommended to be avoided. On the other hand, boat lane crossings in the Raahe archipelago cannot be completely avoided.

Other water traffic is advised to be monitored. This is what I think I did the other day when, while crossing the fairway, the board suddenly disappeared from under me and I fell on my back into the water. The waves raised by the motorboat behind me – not terrifying by any means – shook me more than I had anticipated. The driver of the boat turned thoughtfully to check that it didn’t hurt worse. It was a great gesture. Since then, I’ve popularly landed on my knees well before the boat is on point. Paddling in a kneeling position is safest even when approaching the shore and in shallows and rocks.

According to Traficom, when navigating on water, there are no rights of way but obligations to give way. Traficom’s instructions are easy to read and useful, even though they talk about boaters. Instructions can be found here.

On one canoeing trip, I met a wilderness guide who told me about polarized sunglasses. They prevent light from reflecting from the surface of the water, making it easier to follow what is happening under the surface of the water – then you are less likely to end up there yourself.
It is a good idea to protect yourself from the sun’s rays with clothing or protective cream.
Drinks and other snacks should be taken with you at the top rather than the bottom. Dehydration can be surprising, especially in the heat.

Surprises can also come because of getting lost. When I first tried to paddle from Kylmäniemi via Pitkäkari beach in the direction of Ämmä-Äijä, I ended up accidentally going around Preiskari. All the beaches looked the same from the sea and I couldn’t estimate the distances. When returning to Kylmäniemi via Pikkulahti and the canal, I was really thirsty and tired, because I wasn’t prepared for such a long run. It is also worth noting that in order to safeguard the nesting peace of birds, there is a ban on disembarkation on the most important bird islets and islands in the Raahe archipelago during the nesting season. A list of these places and the dates of the ban can be found (in Finnish), for example, here.

I also learned about the disembarkation ban after getting lost in touring Preiskar. I was able to locate myself on a map of my phone that I hadn’t thought to use before. In front of us was an island called Isokivi, which I read was one of those forbidden to disembark at the time. The south side of the island, at least at the current water level, was overwhelmingly rocky. I didn’t want to try my strength to go around the island from the north side to the headwind. I decided to cross the island on foot via a narrow isthmus found at its southern end. Luckily there didn’t seem to be any birds in that part of the island.
I paddled into my pocket after many years of dreaming. On the previous winter’s skiing trip to Tasku, I had already tried to proactively understand the locations and size of the islands.

When paddling into Tasku, the weather was hot and calm, in sailing slang. The swells were muffled. By the way, they are tricky when they cannot be properly distinguished from a distance and yet they have considerable prescriptive power. We are told that the swells can go thousands of kilometres, but here in the Bay of Bothnia this is probably quite rare.
The instructions recommend that you always plan the route according to the weather, conditions and your own skills. Paddling upwind can be tiring. But it can also be a pleasant activity, especially if you can choose it yourself. In any case, you should always leave some strength for the return trip – a good guide, too!
Read more about safety in raahenrannoilla.fi website.