Despite having 24 hours of daylight, July is likely to receive summer fog that Svalbard is renowned for. This is due to the meeting of wind currents and impacts visibility greatly so may make navigation more difficult. You will be able to use Zodiacs to get to shore and explore certain sites up close though, so will still get good wildlife sightings.
The summer months are also known to be the best months for whale watching in Svalbard. There can be up to 11 species of whale in the region at any one time depending on when they arrive from the south. Look out for minke whales, bowheads and white beluga whales