(I doubt it's possible to get a Teleri translation, but that would be most appropriate.)
I'm thinking something like ocean-sickness or ocean-malaise would work. It's not something a coastal sailor gets, you have to be at sea for a long time. Scurvy makes people listless and their teeth fall out.
gaeron s. ocean
gaearo s. great ocean
gwesg s. weakly, weak
lhîw s. illness
Perhaps a Sindarin version of these Noldor words would work?
cael n. lying in bed, bedridden, sickness
caeleb n. bedridden, sick
Any ideas?
Sickness of the Great Ocean?