well I'll try to mention all the main points
1- for the shell we calculated the submerged height (5 cm ) and you can see the whole height in the picture notation
2- and about the boat is all about the control and collecting information about the weather , so I think we do need neither speed or weight lifting
3- and for the motorization we choose the brushless motors using differentials steering (using Raspberry PI ) as an information's treatment system
4 -but in this phase we need a confirmation for the boat design to start the construction phase as you see we made many different design and we don't know which one is the perfect one !
(it seems that I'm not allowed yet to put even local Image's Url's , so if you can please send to me your E-mail in private , and I'll be glad sending to you the designs )