Pack light - storage space is limited - it's easy to wash and dry clothing by using the pegs provided on deck.
I was unsure whether I needed a wetsuit for snorkeling at this time of year - In the Eastern islands I found the snorkelling warm enough to wear just a t-shirt for sun protection, but in the Western islands it was cooler (actually quite cold in two places) - I had taken a wetsuit type t-shirt, which was fine for all but the two coldest snorkels - I just had to swim a lot to keep warm!
Shoes were recommended, but in the interest of travelling light I managed fine with good quality walking sandals, although I am used to hill walking in them. Closed toe sandals with grippy soles are all you need though.
Take sea sickness tablets with you just in case - we had a couple of days of Spring tide, with quite a swell and a few people needed tablets.
The photographic opportunities are amazing - from reports I read before I went I almost didn't take my 100-400mm lens, but I'm so glad I did as it enabled me to get some really intimate close ups. To get the best out of the trip I'd recommend a wide and a zoom lens. But if you only have a compact, you'll have just as much fun with it.
The entire trip requires cash (not cards) - keep it safe in Quito and ensure that all cash is in $20 notes or less - they rarely accept larger notes. Tipping is an integral part of the culture so ensure you have sufficient to tip the crew and guide in accordance with their service levels.
You'll need insect repellent on a few of the islands (but not on most) - it's always handy to have some with you just in case.
I would highly recommend the two week trip - the greater abundance of wildlife is on the Eastern islands and I enjoyed these islands the most - but my highlights mentioned above all occured on the Western islands.
My only sadness was that Exodus don't run the two week trip in April as I'd have loved to have seen the waved albatrosses who hadn't arrived in time for this trip.
We went in the' hot wet' season, but don't let the 'wet' bit put you off. Temperatures were over 30 degrees, the islands were green (which isn't the case in the dry season) and it only rained during the night on one occasion, so the weather was perfect.
I enjoyed the snorkeling - in places it was good, but in others it was quite murky with not a lot to see. I've been lucky enough to snorkel in the Maldives where the fish are much more plentiful - but the sealions and turtles made up for the it.
Overall a fantastic trip and I'd highly recommend it to all those who enjoy wildlife and a relaxed life on the ocean wave.