海(hai)(hai)(hai)(hai)底(di)電(dian)纜(lan)（submarine cable）是用絕緣材料(liao)包裹的導(dao)線，敷(fu)設在(zai)海(hai)(hai)(hai)(hai)底(di)及河流水下，用于(yu)電(dian)信傳輸。現(xian)代的海(hai)(hai)(hai)(hai)底(di)電(dian)纜(lan)都是使用光纖作為(wei)材料(liao)，傳輸電(dian)話和互聯網信號。全**條(tiao)海(hai)(hai)(hai)(hai)底(di)電(dian)纜(lan)是1850年(nian)在(zai)英國(guo)和法國(guo)之(zhi)間(jian)鋪設的。中(zhong)國(guo)的*條(tiao)海(hai)(hai)(hai)(hai)底(di)電(dian)纜(lan)是在(zai)1888年(nian)完(wan)成，共(gong)有兩條(tiao)，一(yi)(yi)是福州川(chuan)石島與臺灣滬尾（淡水）之(zhi)間(jian)，長(chang)177海(hai)(hai)(hai)(hai)里 另(ling)一(yi)(yi)條(tiao)由臺南安平通(tong)往(wang)澎湖，長(chang)53海(hai)(hai)(hai)(hai)里。

海(hai)(hai)(hai)(hai)底電(dian)(dian)(dian)纜(lan)(lan)(lan)分海(hai)(hai)(hai)(hai)底通信(xin)電(dian)(dian)(dian)纜(lan)(lan)(lan)和(he)(he)(he)海(hai)(hai)(hai)(hai)底電(dian)(dian)(dian)力電(dian)(dian)(dian)纜(lan)(lan)(lan)。海(hai)(hai)(hai)(hai)底通信(xin)電(dian)(dian)(dian)纜(lan)(lan)(lan)主(zhu)(zhu)要用(yong)(yong)于通訊業務,費(fei)用(yong)(yong)昂貴(gui),但保密程度(du)高。海(hai)(hai)(hai)(hai)底電(dian)(dian)(dian)力電(dian)(dian)(dian)纜(lan)(lan)(lan)主(zhu)(zhu)要用(yong)(yong)于水下傳輸大(da)功率電(dian)(dian)(dian)能,與地下電(dian)(dian)(dian)力電(dian)(dian)(dian)纜(lan)(lan)(lan)的作用(yong)(yong)等同,只不過應(ying)用(yong)(yong)的場合和(he)(he)(he)敷設(she)的方式(shi)不同。由于海(hai)(hai)(hai)(hai)底電(dian)(dian)(dian)纜(lan)(lan)(lan)工程被*各國(guo)公認為復雜(za)困難的大(da)型工程,從環境探測、海(hai)(hai)(hai)(hai)洋物理調(diao)查,以(yi)及電(dian)(dian)(dian)纜(lan)(lan)(lan)的設(she)計、制造(zao)和(he)(he)(he)安裝,都應(ying)用(yong)(yong)復雜(za)技術(shu),因而海(hai)(hai)(hai)(hai)底電(dian)(dian)(dian)纜(lan)(lan)(lan)的制造(zao)廠家在(zai)*上為數不多,主(zhu)(zhu)要有挪威、丹麥、日本、加拿大(da)、美、英、法、意等國(guo),這(zhe)些除制造(zao)外還提(ti)供敷設(she)技術(shu)。目前我國(guo)應(ying)用(yong)(yong)的海(hai)(hai)(hai)(hai)底電(dian)(dian)(dian)力電(dian)(dian)(dian)纜(lan)(lan)(lan)仍然需要進(jin)口。

海(hai)底電纜分類浸漬(zi)紙包電纜：適用于(yu)(yu)不大(da)于(yu)(yu)45kV交(jiao)流電及不大(da)于(yu)(yu)400kV直(zhi)流電的(de)線路。目前(qian)只(zhi)限安裝于(yu)(yu)水(shui)深500m以內的(de)水(shui)域。

自容式充油(you)電纜(lan)：適用于(yu)高達750kV的(de)直流(liu)電或交流(liu)電線路。由(you)于(yu)電纜(lan)為充油(you)式，故可以毫無困難地敷設于(yu)水深達500m的(de)海域。

擠壓式(shi)絕緣（交聯聚乙(yi)烯絕緣、乙(yi)丙橡(xiang)膠絕緣）電(dian)纜(lan)：適用于(yu)高達200kV交流電(dian)壓。乙(yi)丙橡(xiang)膠較(jiao)聚乙(yi)烯更能防止樹枝現象及局(ju)部泄電(dian)，使海底電(dian)纜(lan)更有效地發揮(hui)功(gong)能。

“油壓”管電纜(lan)：只適用于數公里(li)長(chang)的電纜(lan)系統，因為要(yao)把極長(chang)的電纜(lan)拉進管道內，受到(dao)很大(da)的機械性限(xian)制。

充(chong)氣(qi)(qi)式（壓力輔助）電(dian)(dian)(dian)纜：使(shi)用浸漬紙包(bao)的(de)充(chong)氣(qi)(qi)式電(dian)(dian)(dian)纜比充(chong)油式電(dian)(dian)(dian)纜更適合于較長的(de)海底(di)電(dian)(dian)(dian)纜網，但由(you)于須在深水下使(shi)用高氣(qi)(qi)壓操作，故(gu)此(ci)增加了設計電(dian)(dian)(dian)纜及(ji)其配件的(de)困難，一般限于水深為300m以內。

海底電(dian)(dian)(dian)纜(lan)(lan)用(yong)(yong)(yong)途 海底通信電(dian)(dian)(dian)纜(lan)(lan)主(zhu)要(yao)用(yong)(yong)(yong)于長(chang)距離通訊網、通常用(yong)(yong)(yong)于遠距離島嶼(yu)之間(jian)(jian)、跨海軍事(shi)設(she)施等(deng)較(jiao)重要(yao)的場合(he)。海底電(dian)(dian)(dian)力電(dian)(dian)(dian)纜(lan)(lan)敷設(she)距離較(jiao)通信電(dian)(dian)(dian)纜(lan)(lan)相(xiang)比要(yao)短(duan)得多(duo)(duo),主(zhu)要(yao)用(yong)(yong)(yong)于陸島之間(jian)(jian)、橫越江河或(huo)港灣、從陸上連接(jie)鉆井平(ping)臺或(huo)鉆井平(ping)臺間(jian)(jian)的互(hu)相(xiang)連接(jie)等(deng)。在一般情況下,應(ying)用(yong)(yong)(yong)海底電(dian)(dian)(dian)纜(lan)(lan)傳輸電(dian)(dian)(dian)能無疑要(yao)比同樣長(chang)度的架(jia)空(kong)電(dian)(dian)(dian)纜(lan)(lan)昂貴,但(dan)用(yong)(yong)(yong)它往往比用(yong)(yong)(yong)小而孤立的發電(dian)(dian)(dian)站作地區性發電(dian)(dian)(dian)更經濟,在近海地區應(ying)用(yong)(yong)(yong)好處更多(duo)(duo)。在島嶼(yu)和河流較(jiao)多(duo)(duo)的,此種(zhong)電(dian)(dian)(dian)纜(lan)(lan)應(ying)用(yong)(yong)(yong)較(jiao)廣泛。