ICR excursions - A few questions

Will be booking a couple of excursions with ICR soon but couple of things crossed my mind. Will it be too hot when we go on 21st July to do a boat trip??? Got kids 10 and 12 so dont want us all to fry too much. Also want to go on the jeep safari which looks fun. What days do they do their boat trips?? Also I looked at the excursions page and couldnt see any discounts for kids, will probably be booking 2 trips and a return transfer so will be quite a bit to fork out. Do they give you a bit off if you book a few things with them??? Just thought Id ask 
