One of the best in my mind is
Bonine. It does not make me drowsy and can be taken when you feel the motion sickness coming on. I usually take it about 2 hours before starting out and it will last all day. At least for me. I do take the patch if I am going on a cruse as it can be on all the while we are out there. It worked real well a couple of years ago when on a cruse after a hurricane we hit 20+' seas we could hardly stand but we did not get sea sick.
But give Bonine a try it works, and the best part you do not get that heavy sleepy feeling either.
Just to give you the reason behind sea sickness as told to me by my Doctor is the movement of the fluid in the inner ear. These pills dry up that fluid and once the sloshing stops you are good to go. That is why your lips get dry and you get thirsty when you use these type of pills.
I hope this helps.
Happy Catching
Paul