Dive Program Report — 2008

It took the better part of their first week for the divers to remove the boats from winter storage, make necessary repairs, and launched.  During this week they retrieved from Rutland a new (used) boat trailer I found on craigslist and received an additional (donated) skiff.  They also replaced the entire deck of the pontoon boat with new marine-grade plywood and welded additional supports on it and reinforced the new trailer so that it could handle the increased weight of a boat laden with wet milfoil.

By May 20th they began diving.  Until late June they are prohibited by the terms of our permit from using the (more efficient) suction harvester, so they were hand picking.  Because the suction harvester can only be used where the milfoil has achieved 10% saturation, they chose locations to hand pick where the milfoil plants are widely scattered, or mixed with abundant local lake weeds.  In late May they picked along the Quinibeck shore, near Lochearn point, and on the north side of Passumpsic point.  They focused on patches adjacent to owners’ docks.  Then they cleaned up the swim areas at Lochearn, Aloha Hive, and Treasure Island in anticipation of campers’ arrival.

Once the suction harvester could be used, the divers focused on the western shore of the north lobe of the lake, from Treasure Island down to Passumpsic point.  Our strategy is to clean out an entire shore of the lake, and this was a manageable choice.  We feel that it is a more effective use of our resources to concentrate the picking in one area rather than removing the same amount of milfoil from various areas around the lake.

Anticipating an early end of the season due to insufficient funding, the divers turned in the last week of August to moving bottom barriers.  Although it might seem simple, both the taking up and laying down the barrier sheets require skill and patience and are fraught with difficulties.  First two divers lift the lengths of epoxy coated rebar off a strip (6 ft. x 100 ft.) of barrier material and hand them up to the pontoon boat for storage.  Then the end of a strip is hooked on the front of the pontoon boat and the boat gently backs over the strip, peeling if off the bottom and trailing it in the water.   Finally the two divers on the deck of the boat pull the plastic in and fold it accordion style on the deck.  Laying it down is pretty much the reverse.  The sheet is trailed behind the slowly moving boat, and “flown” down to its destination on the bottom by two divers in the water.  Placement is critical: each sheet has to overlap its neighbor by about a foot and a half.  Then each sheet is “burped” – trapped air is squeezed out from under – and pieces of rebar are placed every dozen feet or so along the top.  More than a little wind can slow the process considerably, both lowering visibility beneath the surface and making precise maneuvering of the pontoon boat difficult.  (click on the photo above for more pictures and a better explanation)

In November we are required to file a detailed report of our activities with the state.  At that time I will post specifics of the amounts of milfoil removedand bottom bariers relocated here.

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