Single engine amphibian airplane pilot reported a gear up landing. The pilot reported they muted the audio landing gear down signal and did not visually check to see if the gear was down before landing.

Narrative

First flight of the spring flying season for my Found Bush Hawk XP Amphibian (FBA-2C1) 10 miles southeast of ZZZ; at 3000 ft. over water with floats. Entered left upwind for Runway XX approximately 4 miles from the airport. Flaps down two notches. Held off lowering landing gear as the aircraft was still headed over water for 3 more miles. Turned left crosswind over land; then turned downwind. Mid-field called out gear down and toggled switch. One other aircraft in the pattern turning left base to final for Runway XX. I'm searching for traffic. Have traffic at 9 o'clock on final. Muted landing gear position with 4 lights; turned left base on to final. Landed Runway XX after about 1500 ft. and skidded about another 500 ft. while steering the aircraft to the west side of the runway in case other aircraft had to land.Contacted ZZZ Unicom for assistance. Dispatched a safety truck to provide flashing lights for warning. Allowed a Cessna 150 to land on the far end of Runway YY. Diverted another aircraft to ZZZ1 for standby return. Mobilized my aircraft mechanic and a crew of 4 persons and chalked up the Bush Hawk Amphib to enable extending the landing gear; which was still in the retracted position when I landed. Completed the task in about an hour. No significant damage to the aircraft; other than the skids on the floats will have to be repaired. No injuries incurred by me; and no other persons anywhere near to the site of the incident. No damages to any third party property.The last item on the landing checklist is to physically look at the landing gear aids. When I had the aircraft that was landing on final at my 9 o'clock; all I had to do was look over my left shoulder at the red warning dowel that protrudes up just above the floats when the wheels are in the UP position. Normally; when I have passengers; I ask them to help me watch for this signal to ensure the wheels are in the right position. Secondly; muting the landing gear broadcast was something I regret doing; because it would have provided further chances to signal to me that the wheels were still UP. I've been flying for xx years and never had an accident or incident. I'll certainly remember these going forward