On the Mardaites

Cambridge History of the Byz. Empire, p. 382: “Another instrument of Byzantine diplomacy took the form of the unruly bands of Mardaites that Constantine IV unleashed to raid along the north Syrian coast and to infest its hills. The hardy Mardaites were few in number, and proved disproportionately successful in disrupting Muslim control over northern Syria. A troublesome and temporary Byzantine tool of the late 680s and early 690s, they were probably of Armenian origin. Their operations on behalf of the Byzantines were all the more effective thanks to the protracted second fitna, which lasted from 683 until 692: the Muslim authorities found it difficult to check the Mardaite raids while they were seriously distracted by their own internal strife. Justinian II (685-95, 705-11) withdrew the Mardaites from the mountainous regions around Antioch and the north Syrian coast sometime around 687, shortly before sending Leontius to Armenia in command of a strong expeditionary force; in 690 Caliph ‘Abd al-Malik restored Antioch to Muslim rule. The city may have slipped out of Muslim hands because of the Mardaite raiding and the distractions of the fitna.”

Nicolle, Romano-Byzantine armies, p. 16: “One group who played a significant role in the early clashes with the Muslims were the Mardaites (Arabic: Jarajima) of the Syrian coastal mountains. Whether the Emperor stirred up their guerrilla resistance is unknown, but the Byzantines certainly took advantage of their actions. These Mardaites have been identified as being descended from Byzantine limitanii, but are more likely to have been superficially Christian mountainfolk who resisted any authority - including the previous Byzantine rulers. After being defeated by the Muslim Arabs in AD 708 some came to terms with their new rulers, others migrated to Byzantine territory to settle as warrior communities in southern Anatolia, Greece and some Greek islands.”

Dixon, 'Abd al-Ameer 'Abd, The Umayyad caliphate 65-86, p. 122: “Another threat to ‘Abd al-Malik’s position in Syria at this time came from the Byzantine Emperor, who, encouraged by the political confusion of the time, stirred up the Jarājima (Mardaites) against the ‘Arabs. According to Balāduri, a Byzantine cavalry came into the Amanūs district (Lukām) and penetrated as far as Lebanon. This force was joined by a large number of Jarājima, Anbāṭ (Nabateans) and runaway slaves. The caliph found himself compelled to make a treaty with them, guaranteeing them a weekly payment of one thousand Dīnārs. Then, following the precedent of Mu’āwiya, he offered peace terms to the emperor.

“The contents of the treaty between them are preserved only by the Christian sources. According to this treaty, the caliph agreed to pay 365,000 gold pieces, 365 slaves and 365 thoroughbred horses; he had also to surrender half of the tribute from Cyprus, Armenia and Iberia. In return, the emperor Justinian II agreed to withdraw the Mardaites, and he recalled 12,000 of them to be settled in Byzantine territory. It is interesting to note here that the Christian sources reproach the emperor for denuding the frontiers in this way.

“Following the account of Balādurī, after signing the treaty, ‘Abd al-Malik sent one of his trusted men, Suḥaim ibn al-Muhājir, to the Byzantine officer commanding the Jarājima. Suḥaim succeeded in winning his confidence by pretending to take his part against the caliph. Then Suḥaim used his troops, which he had hidden, to make a surprise attack, killing the officer and his Greek followers. As for the Jarājima, they were guaranteed Amān; some went away and settled in the villages of Ḥimṣ and Damascus, while the majority of them went back to the Amanūs; the Anbāṭ returned to their villages and the slaves to their masters, while others entered the caliph’s service.”

On Byzantine naval raids on the Levantine coast during this period:

Lawrence I. Conrad, “The Conquest of Arwād: A Source-Critical Study in the Historiography of the Early Medieval Near East,” in Cameron et al., Byzantine and Early Islamic Near East, Vol I, p. 338-39: “In Umayyad times, and especially during the caliphate of ‘Abd al-Malik (65-86/685-705), the Greeks mounted raids on various cities along the Syrian coast, including Tyre, Acre, Caesarea, and Ascalon, encouraged Mardaite depredations within Syrian territory as far as Mount Lebanon and Palestine, and maintained pressure on the Umayyads along the frontier. All this provoked extreme anxiety among the Muslims of northern Syria (still, we must recall, a small minority of the population), and it should come as no surprise that in late Umayyad times the possibility of yet another Byzantine seaborne attack was still a matter of considerable concern to them.”

The Jewel of Muscat - a successful arrival into Kochi, its first port of call.

A site you should absolutely check out is this. The government of Oman funded a project to build a replica of a 9th-century Omani seagoing vessel, using traditional materials and methods, and sailed her to Singapore following routes and using seafaring and navigation methods that would have been used at the time. Although it's a couple centuries removed from your period of research (and mine) and is likely a different style of vessel than what would have been used for military purposes, the site is rich with detail about shipbuilding and seafaring methods for the period. Best of all, it includes a wealth of fascinating videos. Vastly interesting.

A vast trove of information on Islamic ships and shipbuilding is here.

Another great possible source is an article called "Aspects of Arab Seafaring: An Attempt to Fill in the Gaps of Maritime History," Ed. Y. Y. al-Hijji and Vassilios Christides, Athens, 2002.