Late Season Water Levels

As the sailing season progresses the water level usually decreases in height unless we are fortunate enough to receive a real downpour that postpones the retrieval of your boat in a safe manner.

The factors to be considered are

# 1 With the boat sitting on the trailer, measure from the waterline to the ground ( with a keel boat measure from the waterline to the ground also but make a note of the distance from the ground to the plate that the keel rests on as this determines how much water you need). If you add this figure to the stated depth by the manufacturer, the sum of these two figures (depth according to the manufacturer's data  plus the trailer height) should equal the waterline to ground measurement.

#2 Measure the distance from the center of the trailer wheel (if single axle trailer) to the center of the rear wheel on your tow vehicle. If your trailer is a 4 wheel trailer, as most keel boat trailers are, measure from the center of the rear trailer axle to the center of the tow vehicle rear wheel.

#3  Decide how far you want your tow vehicle rear wheels to go into the water bearing in mind that most rear wheel drive vehicles have a vent for the differential mounted somewhere on the rear axle and if water enters your differential thru this vent, you could be facing some very expensive repair bills. My recommendation is that it is good practice to have your rear wheels no further than rhe water's edge.

#4 From the above photo it is easy to determine that with the tow vehicle's rear wheels at the water's edge, we would need 32+" of water depth, 19 feet from the water's edge, to float the Matilda off and on the trailer.

#5 If we go back to the Abbott with the waterline 62" above the ground and a distance of approx. 20' from the center of the rear trailer wheels to the center of the tow vehicle rear wheel, how far down the ramp would the trailer's rear wheel be and how deep would the water be at the trailer's rear wheel when the tow vehicle's rear wheels are at the water's edge when the water level is at 110' on the ramp??

How deep would the water be at the trailer's rear wheel if the water level on the ramp was 80'??  Suggestion- refer to projected water level chart under ramp characteristics.

How long a tongue extension would be necessary to ensure the boat would go off and on the trailer at the suggested levels on the ramp??