Bolger's Fast Brick Design
I have recently completed work on the launch to be carried on the "Great Sea" or Bolger's Double Eagle design. The fast Brick is a combination lifeboat and tender and is 10' X 3' 10". The boat is constructed with plywood and foam in the sides and bottom, basically a sandwich of ply/foam/ply. Two inch foam is used throughout with the sides being 1/4"ply - 2" foam - 1/8" plywood on the inside, and the bottom being 1/2" ply - 2" foam - 1/8" inside. The foam adds a lot of floatation but there are three other water tight compartments.

This design can be built in any length from 8' to 12' on the same beam. My version is 10 ' long and I reduced the beam from 48" to 46" to fit the space I have on deck. The boat will plane with minimal outboard power, I plan use a 10 hp Honda. There is a sail rig with a leeboard and the boat should row fairly well. When sailing or rowing the boat should be balanced bow down to lift the transom out of the water.

The following photos show the completed boat. If you would like to see the construction process there is an excellent website showing the construction of the same design in a 12' version here.
The transom showing the offset rudder with the tiller folded down. Also the outlet and white hose for the hand bilge pump, the splashwell drain and an eyelet for a dockline.
The other side of the rudder showing the retracted  blade.
The rudder assembly ready to sail.
The leeboard on the port side. One line to raise the board, one line to lower it. The round black piece is UHMW polyethylene
The lowered mast and forward thwart.
From the bow looking aft. The forward hatch, the aft thwart and the bilge pump are shown.
Looking down into the splashwell. The deckplates access water tight storage
The bow cutwater.
The bilge pump showing the recessed area or sump in the floor. I made an engineering mistake in placing the aft thwart too close to the bilge pump so that you have to remove the thwart to use the pump.
This photo shows the Fast Brick but also shows the completed mast for the big boat, 40' long out of 8" aluminum pipe.