Israel has finally decided to retire its three Seascan naval patrol aircraft and replace them with UAVs. Israel first announced doing this back in 2008 but changed its mind in 2012 and ordered the Seascans be refurbished and kept in service because in 2010 Israel discovered $100 billion worth of natural gas off shore, near the Lebanese border. That discovery meant more maritime recon capabilities were needed. But since 2012 Israel discovered that even with a refurb the Seascans would be too expensive to maintain and that the Heron I UAV had become more reliable and capable as a maritime patrol aircraft.
Senescence (old age) in aircraft has become a growing problems since the 1960s and while you can keep rebuilding older aircraft, once unmanned replacements came along, rebuilding was no longer as effective as it had long been.
This is all about money, big money. The threat here is the fact that Israel and Lebanon do not have diplomatic relations, and the Lebanese Hezbollah terrorist organization constantly calls for war with Israel, there is a greater need for offshore security. Worse yet, Turkey has threatened to intervene on Lebanon's side in the boundary dispute. This dispute has been brewing for some time. In 2004 Israel discovered about $20 billion worth of natural gas off the coast and that led to more and more discoveries. Safeguarding this natural resource has become a top priority. When the larger field hits peak production by the end of the decade Israel will no longer have to import $4 billion of fuel a year.
Since the early 1980s the Seascan aircraft have been Israel's main maritime patrol aircraft. These are modified versions of the Israeli- made Westwind executive jet. This ten ton aircraft has a seven man crew, is equipped with search radar, and can carry missiles. The Seascan has an endurance of six hours. The planned refurbishment was to repair or replace worn structural elements and upgrade the electronics.
Israel is still adding Heron UAVs to its maritime patrol force. The 1.1 ton Heron can stay in the air for 30 hours or more and has a payload of 227 kg (500 pounds). This will include search radar for maritime patrol. Using the Heron for maritime is a lot cheaper than the Seascan and since 2012 new tech has made it possible to equip the Heron with as capable a radar as the heavier one used by Seascan.