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Croatia Travel Advice


Please read each of the sections below carefully. They provide important information about your Operation Wallacea expedition in Croatia. Should you require further assistance please do not hesitate to contact your nearest Operation Wallacea office.

Travelling to and from the expedition


The terrestrial only and the terrestrial & marine expeditions start in the Krka Valley on a Thursday at 1600hrs. You need to book your international flight to arrive into either Zadar (ZAD) or Split (SPU) on Thursday before 1530hrs.

The marine only expeditions start on Silba Island on a Thursday at 1600hrs. You need to book your international flight to arrive into either Zadar (ZAD) on Thursday before 0800hrs or Split (SPU) anytime Wednesday the day before your expedition.


The terrestrial & marine and marine only expeditions finish on Silba Island on a Wednesday at 0730hrs. You need to book your homeward international flight to depart from either Zadar (ZAD) on Wednesday after 1100hrs or Split (SPU) on Wednesday after 1200hrs.

The terrestrial only expeditions finish in the the Krka Valley on a Thursday at 0900hrs. You need to book your homeward international flight to depart from either Zadar (ZAD) or Split (SPU) on Thursday after 1200hrs.

Internal Travel

When you arrive at your international airport (Split/Zadar) you will be met by an Opwall representative and transferred to your expedition start point on the Thursday (via bus for the terrestrial site and via bus and ferry to the marine site). If you are arriving into Split for the marine only expedition, you will require to overnight in Split on the Wednesday before starting your transfer to the expedition site on Thursday. On the day your expedition ends you will then be transferred back to your international airport for your homeward flight.

Please note internal travel is an additional cost to the Operation Wallacea expedition fee and your international flights, once your international flights have been arranged and uploaded to your portal we will be able to help organise your internal travel package based on exactly what you need. To find out more please check out the costs to consider tab on your expedition page on the website.

Additional Nights

As part of the internal travel package it is possible to arrange additional nights in Split and Zadar before and after your expedition, and the relevant airport transfers. The cost of these extra nights will be added to your internal travel package quote.

Booking International Flights

Please ensure when booking your international flights that the cost of your ticket includes hold luggage. 

Research Assistants and Dissertation/Thesis Students

You are welcome to book your flights with your preferred travel agent, just ensure to check our flight arrival and departure information thoroughly. A great place to start looking for flights is Sky scanner, Expedia or Trip UK. If you are a volunteer from the UK or Ireland when you book an expedition with us you can contact our preferred travel partner ISON Travel, who will provide you with competitive quotes for your international flights.

ISON Travel
Tel: 0203 405 7778
E-mail: opwall@isontravel.com


If you are a student in the USA or Canada, we recommend trying Student Universe for your flights as they give discounts to students. You are welcome to book your flights elsewhere, however our partnership means that they generally provide the best price, are familiar with our expeditions and give excellent service.

Student Universe US
Tel: +1 800 272 9676 (Toll-free within the US and Canada)

Student Universe CAN
Tel: +1 800 761 0060 (Toll-free within the US and Canada)

Once you have booked your international flights, please enter the details on the Opwall portal.

School Groups


School groups that have chosen a fully inclusive expedition package do not need to book international flights or internal travel. Operation Wallacea will be in contact with the group leader directly and will provide you with a fully inclusive quote for your international flights, internal travel and expedition costs.


Schools also have the option of having Opwall search for the best flight deal for the group and once the school group leader has approved the purchase, the tickets are then bought by Opwall at cost on behalf of the school.  A flight booking fee per person is charged for this approach.  Details of the flights for the group will be entered onto the portal by the Opwall staff booking the flights.

Alternatively, if the school has reliable travel partners then they can book the flights themselves and just pay Opwall for the expedition and internal travel costs. Under this scenario the group leader needs to enter the flight details through the Opwall portal and email a copy of the itinerary or E-ticket to flights@opwall.com.


We advise citizens of all nationalities to have at least 6 months validity (period before expiry) on their passports at the time of your arrival into Croatia.

UK citizens are currently advised by the FCO that their passport only needs to be valid for the duration of their stay in Croatia. However passport rules are likely to change following BREXIT and so it is prudent to have at least 6 months validity.


If you are a UK, EU, US or Canadian citizen you do not need a visa to enter Croatia. Most other nationalities will need to apply for a visa via their nearest Croatian embassy. http://www.mvep.hr/en/consular-information/visas/visa-requirements-overview/


Any UK, Australian, UAE, Canadian, USA, Japan and South Korea nationals travelling to Croatia aged between 18-70 will need to apply for an ETIAS, the cost of which is €7 (EUR).

Please see:

You will need a payment card to cover the €7 fee. You can use a variety of online payment options to pay the fee.
Applicants who are under 18 or above 70 years of age are exempt from this payment. Also exempt are family members of EU citizens or of non-EU nationals who have the right to move freely throughout the European Union.


For all COVID-19 information please visit this page.

Carbon Offsetting

By joining an Operation Wallacea expedition you are contributing directly towards the study and protection of threatened biodiversity, bringing significant financial benefits to small local communities, and working towards protecting valuable carbon stocks from deforestation. We are extremely proud of the impact we and our volunteers have had over the past two decades, creating a significant benefit to the environment.

However, we want to do more. Specifically, we want to make Operation Wallacea completely carbon neutral. As an organisation we will now be offsetting our own emissions from staff travel (both road and air) and from running our offices. But we also want to encourage all our participants to offset, at the very least, the carbon emissions from their own international flights – and ideally more. To do this we will be supporting the Wallacea Reforestation Initiative in partnership with our sister charity the Wallacea Trust (UK Charity 1078362), and you can read more about this exciting project here that takes a new approach to tropical reforestation that benefits not only climate, but biodiversity and livelihoods too.

How to Calculate Your Donation Amount

The first step in calculating your donation amount is to work out the total estimated amount of carbon your flights will emit into the atmosphere. To do this you need to take the exact flight routes you are booked on to for your summer expedition, and run these through the UN’s International Civil Aviation Organization (ICAO) carbon calculator. This calculator can be found here.

This gives you the Total passengers’ CO2/journey (KG), which you will then need to convert into tonnes. 1 KG is equal to 0.001 ton, so you then need to divide your figure in KG by 1000. We usually assigned a value of $12 USD (or £10 GBP) per ton of carbon, therefore to work out this donation amount, you would need to multiply your ton value by either 12 or 10 depending on your currency.

For some of your flight legs, you may not be able to find your destination airport on the calculator, in this circumstance, we would recommend using the nearest airport (ie. for Croatia using Zagreb airport).

If you’re happy with an estimate rather than calculating the costs yourself, a £15 donation will cover the carbon produced by the flights in more than 95% of cases.

To donate, please visit the Wallacea Trust page and click ‘donate now’ at the top.

Wallace House, Old Bolingbroke, Spilsby, Lincolnshire PE23 4EX, UK
| +44 (0) 1790 763194 | info@opwall.com