On June 8 page 3 of the message board, my original post makes a glaring ommission!, which Mr Grumpy immediately spotted ; i have just arrived back to discover it. I failed to point out that it was the end caps on my poles which caused the problem of contact with the riverbed . The depth and speed of flow of the water the reason . I have now removed them ready for next time !. So apologies to all and thanks for your patience , bill h. hope to see you again next May.