Mosquitoes and ticks in Masuria: how to protect yourself on a yacht and on shore

Mosquitoes and ticks in Masuria: the short version

On a boat trip in Masuria, you are protected by repellent used according to the label, mosquito nets on the hatches, long sleeves in the evening, checking your skin every time you come back from the shore, and vaccination against tick-borne encephalitis (TBE) before the season. Caution makes sense here, because the Warmian-Masurian Voivodeship has the second-highest incidence of tick-borne encephalitis in Poland: in 2025 it was 9.9 cases per 100,000 inhabitants, compared with a national average of 2.5.

The trouble usually starts near the shore: in the evening at the quay, on a wild mooring by a forest and on a walk through the grass near the port.

How many cases there are in the region

Data: the NIZP PZH (Poland's National Institute of Public Health) and GIS (Chief Sanitary Inspectorate) bulletin “Infectious Diseases and Poisonings in Poland in 2025”. In its report for 2023, the sanitary inspectorate in Olsztyn wrote plainly about the endemic occurrence of infected ticks in the voivodeship and noted that most TBE cases are in the eastern districts. According to NIZP PZH, ticks are active from April to October, with a stronger period in spring and summer and a weaker one in autumn. So during the May long weekend, the summer holidays and in September, ticks are active.

Where you will meet ticks and where mosquitoes

Ticks live in damp places with lush vegetation, that is in forests and along their edges, in thickets, in meadows and on lake shores, as the sanitary inspectorate in Elbląg describes. You bring them onto the yacht from the shore, on your trouser legs, in grass stuck to your shoes or on your dog. In children, in around 70% of cases the tick is on the head, along the hairline and behind the ears, and in adults behind the knees, in the groin and on the belly.

Mosquitoes and Culiseta mosquitoes bite most at dusk and when the air is very humid. A study of mosquitoes carried out in Masuria in the 1990s, around Kętrzyn, showed that the most common species there stays close to large lakes with rich shoreline vegetation, and that the females are most likely to attack late in the evening. Blackflies bite during the day, in full sun, and according to the sanitary inspectorate their bites cause swelling and redness more often than mosquito bites do. In Poland, a mosquito bite itself usually ends with itching. West Nile fever occurs here only in isolated cases: two cases nationwide in each of 2024 and 2025, and none in the Warmian-Masurian Voivodeship.

How to protect yourself on a yacht

The sanitary inspectorate advises covering windows and doors with fine mesh and not opening them in the evening with the lights on. On a yacht, the same applies to the hatches and the companionway. If the yacht has no mosquito nets, ask the owner about them or bring your own mesh that you can fix in place without glue, and in the evening only switch on the cabin light after closing the hatches. For the evening at the quay and for going ashore, wear long trousers tucked into your socks, closed shoes and a long-sleeved shirt.

Only choose a repellent that has a marketing authorisation, with its number shown on the label. The label also gives the age from which it can be used and how many times a day. These limits vary even for the same substance: a 20% icaridin product from one manufacturer is approved from the age of 2, and one from another manufacturer from the age of 6. Don't apply repellent to broken skin or directly to your face; put it on your hands first. Don't apply it to a child's hands, because they end up in the mouth and eyes, so an adult puts the product on their own hands and then on the child's face. If you use sunscreen, according to the US CDC you apply the sunscreen first and only then the repellent. Permethrin products are for clothing, never for skin.

Manufacturers intend mosquito coils for use in the open air, and the CDC advises not to breathe in their smoke. On deck a coil is a smouldering object, so place it away from lines, cushions and sails and don't leave it unattended. On a wild mooring by a forest, keep repellent and nets within reach from the evening onwards, because the grass and bushes are right next to the hull.

How to remove a tick on a yacht

1. Grab the tick with tweezers or a tick lasso as close to the skin as possible.
2. Pull upwards with a firm, smooth movement, without squeezing its abdomen.
3. Don't smear it with grease or anything else, and don't burn it, twist it or crush it.
4. Disinfect the bite site, for example with surgical spirit, and wash your hands.
5. If part of the tick has stayed in the skin or you cannot remove it, see a doctor or nurse at a clinic or at the out-of-hours (night and holiday) medical service.

According to pacjent.gov.pl, removing a tick quickly, ideally within 24 hours, significantly reduces the risk of disease. The exception is TBE, because the virus is in the tick's saliva and, according to NIZP PZH, even quick removal does not reduce the risk of infection. NIZP PZH also does not recommend having the tick tested. Over the following weeks, watch the bite site: erythema migrans (a spreading red rash) appears after a few days at the earliest, usually around day seven, but not in everyone. A rash, high fever, a severe headache or neurological symptoms are a reason to see a doctor. A tick lasso and tweezers should be in the first aid kit you take on a boat trip in Masuria.

TBE vaccination before the season

Poland's Protective Immunisation Programme for 2027 recommends vaccination against tick-borne encephalitis for people staying in areas where the disease is more common, in particular tourists and families with young children. The basic schedule is three doses, and according to NIZP PZH the first is best taken in February or March, so that you are protected from the start of the tick season. In the accelerated schedule, the second dose is given two weeks after the first. Vaccines are available from the age of one. The vaccination is recommended but you pay for it, and you can get it at a primary care (POZ) clinic, at a private clinic or, as an adult, at a pharmacy that offers vaccinations. Whether and when to get vaccinated is something you decide with your doctor.

A trip with children is planned a little differently, so also take a look at our one-week boat trip plan with children. Check your dog after a walk on the shore too, especially if you choose a yacht charter with a dog.

Frequently asked questions

Are there a lot of ticks in Masuria? Yes. The sanitary inspectorate has described the endemic occurrence of infected ticks in the Warmian-Masurian Voivodeship, and the incidence of TBE here is almost four times higher than the Polish average.

When are ticks active in Masuria? According to NIZP PZH, from April to October, most of all in spring and summer. They are most often found in forests, thickets and tall grass on lake shores.

How do I remove a tick on a yacht? With tweezers or a tick lasso, gripping it as close to the skin as possible and pulling firmly upwards. Don't smear it with anything or burn it, and disinfect the bite site and watch it for several weeks.

Which mosquito repellent can I use on a child? One that has a marketing authorisation and whose label allows use at your child's age. Age limits vary between products, even with the same active ingredient.

When do mosquitoes bite most in Masuria? At dusk and when the air is very humid. Blackflies bite during the day, in the sun.