First, let me start out by saying that the review below is based on the customer service (or lack of it) that I received and not on the actual excursion, as I never made it out on the boat.
I was all set up to go on the snorkeling excursion, however the morning of, I felt a headache and had a minor sore throat. It was nothing that would stop us from going snorkeling, however rather then take a chance, I took a rapid Covid test, just to make sure. Surprisingly, my test came back positive. Therefore, I emailed Sebago via Viator, asking them to provide a refund due to this last minute item. However, I was told that I couldn't get a refund, as it was less then 24 hours before the excursion.
I emailed them back again asking them to reconsider, explaining how I could have easily came on the excursion if I really wanted, but did not want to put their employees and other snorkeler's at risk. However, they would not budge. I understand that they have a policy when it comes to refunds, however I believe they should also be flexible, when it comes to things like Covid (just like other industries are accommodating during the pandemic). Otherwise, someone else, who is in a similar situation, might think twice before cancelling.
Therefore, please be careful when booking with this company, as you might not like the customer service you will receive, in case of any issues.