We have the standard dinghy davits on the back of our
Lagoon 39. We too were concerned with our Highfield 9.8 dinghy swinging on the davits while making passage.
First, we do as previously mentioned, raise the bow 6"-8" above the transom so any rainwater or seawater that enters will leave thru the transom drain
plug. Naturally we remove the drain
plug.
Second we remove the 9.8 Tahatsu
outboard and lock it to the transom
safety rail
engine mount.
Third for the bow, we simply tighten the bitter end of the painter (one end of painter is previously connected at center bow eyelight) by taking in all the slack, cleat to the starboard inboard 12" stern cleat and coil the remaining painter around the cleat and finish with a half-hitch. The dinghy is pulled tight up to (clearance 1/2") but not quite touching our six-person lift raft stored center on transom. This position prevents nearly all swinging and causes minimum if any chafing along a three foot section where the dinghy makes periodic contact with the life-raft cannister.
Fourth, we tie a bowline through the port-side dinghy transom lift hole located in the transom of the dinghy (using three-strand 8mm dacron line). The bitter end is then cleated to the port inboard 12" stern cleat using a standard
mooring cleat hitch. The dinghy once again is pulled tight nearly touching the
fiberglass but leaving a clearance of 1/2". Again this line is 8 mm three-stand dacron and left in the dinghy when not in use. Length of line is approximately seven feet.
This we feel is a simple solution that doesn't create other problems to address or other
equipment to keep up with. Obviously, this solution is inexpensive. Nor does it require any drilling or special brackets or tie downs.
This non-glamours, low-cost solution works for us on long passages through-out the
Caribbean in 6-10 ft seas and stopped the dinghy form swinging while not allowing chafe on either the lifting lines or dinghy. The Highfield dinghy is a light weight dinghy and after removing the motor only the oars and 5 gal
fuel tank remain.
The Lagoon 39 with all its options is complex enough. We first look for non-complex solutions to most of our
boating needs. Throwing
money at solutions is often not the ideal solution when it comes to unattended consequences (yin and yang).