Adam,
You are probably running into a lack of famialiarity with the Lake as a type. They are not a common aircraft, and insurer's sometimes aren't familiar with how to assess their associated risks. Some of those risks are:
Land on the runway with the wheels retracted = bad. Some damage and some recovery costs. Land in the water with the wheels extended = destroyed airplane, people in the water (maybe drowning) and much more expensive recovery ('cause it was not at an airport, and possibly not even near a road). Pull the plane too far onto the beach, then push it back in and takeoff on the water, and you could be taking 500 pounds of water with you unexpectedly = bad for gross weight and C of G. Allow water in the bilge to freeze during your flight, and the flight controls can freeze solid = bad for landing. A trained float plane pilot will have a real challenge flying a Lake well. They fly very differenly on the water that a float plane - though excellently. They can be challenging to dock compared to the float plane, so things can get broken off the plane (or dock I guess!). After those risk factors, you have to add all of the variability of flying off the water at all.
They are a very good airplane, for the use for which they are intended, and a delight to fly. If you want more information, and are serious, I suggest you come to Canada, and fly one first. One of my clients is the Canadian expert on Lakes. His company is:
Lake Central Air Services Check out the section on the Lake fly in every September.
The following is a Lake I did the design approval flight testing on, which included active vibration testing of the boom (shaking it with a motor in flight to see if it comes off), a dive to 110% of Vne, and spinning. The plane was a delight, and serves its owner well doing its work. There is also an amphibious flying boat expect in Norway with whom I could connect you if you would like to PM me.
Pilot DAR
