What is unusual about each of these seven sentences?

1. It's a craft that might tip over in the ocean.
2. You cover a mattress with one of these.
3. It's a feature on which a tire might be rated.
4. It's a feeling about a poisonous adder.
5. It's a weapon a cavalryman bears.
6. It doesn't necessarily bring rain, but it could.

HINT:
It has to do with the last word in each sentence.

Answer: 

The last word in each sentence can be anagrammed into a word which answers the question suggested by the sentence.

1. OCEAN - CANOE
2. THESE - SHEET
3. RATED - TREAD
4. ADDER - DREAD
5. BEARS - SABER
6. COULD - CLOUD