We have narrowed down our search to two boats that are in freshwater in Texas and will be walking through them in a week or two. Are there any particular questions we should ask since we are fairly new to houseboats? One is a 2002 18x100 and the other a 2002 with a refit this year 18x80, both are Sumerset's. Can an accurate marine survey be done with the boat in the water, or would it be advisable to pay the extra money to have it pulled? My big concern is galvanic corrosion. Any advice would be greatly appreciated...thanks in advance!