Ask who ever you are getting your TT insurance from a few questions like this,
Is there equal replacement value insurance? Meaning 2 years after you get it and you have a total loss, do I collect a "depreciated value" or do I get a new camper of equivalent value when I purchased mine new? And what about at 5 years then then at 10 years?
If I am camping off my property and unhooked from the truck, I have a fire in the camper, it totals my camper and the rig next to us, what coverage do I have agasint my camper (because I was unhooked from the truck) and the damage to the rig next to me?
Do they have a dissappearing deductible for years of no claims? You are starting at a $1,000 deductible now.
As far as water damage, outside of the factory warranty and it is caused by bad caulk or frozen pipes and not a tree falling on the camper, odds may be favorable you may be out of luck.
The best insurance against water damage is educate yourself on how campers die from water intrusion. And be to the point of anal on roof caulking inspections at least 2 times a year, better is 4 or more as you wash the roof, always be looking. Any joint in the camper outside, windows, doors, edge corners, cargo holes, DOT lights,awning bracket mounts you name it, understand how they infect the camper with water... The older they get the more susceptible to water intrusion. This can start on year 2 sometimes year 1 when the factory messes up.
The next best way to augment against water damage, store the camper inside while not camping. I know this is not in the cards for every one, so be extra anal about the water damage education.
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10 RA, 21,000 GCWR, 11,000 GVWR, upgraded 2 1/2" Towbeast Receiver. Hitched with a 1,700# Reese HP WD, HP Dual Cam to a 2004 Sunline Solaris T310R travel trailer.